2009–2011: Early career Watts was recruited by the
Melbourne Football Club with the first overall selection in the
2008 national draft. Drafted at seventeen years of age, he was in the last draft where a player could be recruited at seventeen, with the AFL requiring that, effective from the
2009 AFL draft, a player must turn at least eighteen years of age in the year they are drafted. The hype placed on him by the club was high when he was presented with the number four guernsey by six-time Melbourne premiership player,
Ron Barassi—a guernsey number previously worn by
club legend and the winner of ten premierships with the club as a player and coach,
Norm Smith—in a ceremony at the
Melbourne Cricket Ground (MCG) two days after being drafted. Completing year twelve in 2009, the need to manage school with football Watts played his first match for the year in the
Victorian Football League (VFL) reserves for Melbourne's
affiliate team, the
Casey Scorpions, in the middle of April; against , he recorded twenty disposals and a goal. Spending two weeks in the VFL reserves, he was promoted to the VFL seniors for the forty-two point win against where he recorded sixteen disposals and three goals. A bye in the VFL a week later allowed him to return to
APS football, playing for
Brighton Grammar; a rare occurrence of an AFL-listed player playing school football, he kicked three goals in a draw against
Melbourne Grammar. He spent the next three weeks in the VFL, where he recorded twenty-two and twenty-three disposals in the second and third week respectively, which saw him earn a spot in the AFL side for the annual
Queen's Birthday clash against at the MCG in round eleven. With the Queen's Birthday match marketed as the club's biggest match during the year, then-senior coach,
Dean Bailey, promoted the debut of Watts by imploring fans to come along so they "will look back at this time in three, four or five years to see where it all began and to be able to say I was there the day Jack Watts made his debut". His first touch saw him gang tackled by three Collingwood players, another contest saw him beaten by
Martin Clarke, which led to a Collingwood goal; Collingwood captain,
Nick Maxwell, gestured to Watts "that's your goal, mate! Welcome to real footy". The team ultimately lost by sixty-six points with Watts recording just eight disposals, a mark and a behind, playing on the half-forward line. He retained his spot the next week for a forty-eight point loss against at
Etihad Stadium in which he kicked his first AFL goal. Recording nine disposals in his second match, the excitement surrounding Watts quickly turned to criticism with his school football coach and former AFL footballer,
Robert Shaw, stating that he was not ready for AFL football. Premiership player and coach,
Leigh Matthews, said he had not seen anything in Watts' first two matches to warrant him being the number one draft pick. He played his third and final AFL match of the year the next week in the fifty-five point loss against at the
Gabba, where
The Age journalist, Andrew Stafford, noted his confidence looked low. He spent the remainder of the year playing in the VFL. A quad strain in February 2010 curtailed Watts' pre-season, and a subsequent back injury further slowed down his preparation for the season. He was placed on a modified program, which meant he was unlikely to play in the AFL early in the season, instead easing him into VFL matches. He played his first match for the year in a VFL practice match against the
Northern Bullants; he gathered nine disposals, playing in just the first half of the match. Round five in the VFL saw him kick four goals and he was named in the best players in the seventy-five point win against Coburg. His performance in the match saw him called up to the AFL side the next week for the round eight match against at the MCG. The match drew attention as it was the first time he would play an AFL match against
Nic Naitanui, who was drafted with the pick directly after him in the 2008 draft. In the twenty-nine point loss, he recorded fifteen disposals and five marks. Watts retained his spot the next week for the round nine match against at
TIO Stadium in
Darwin, and kicked two early goals to help the club win by one point. He maintained his spot in the side for the remainder of the year, even after recording just three disposals against in round eleven, He played fifteen games in his second season, kicking ten goals, with former Essendon forward and three-time
Coleman Medallist,
Matthew Lloyd, stating Watts would be "ecstatic" with his season and he "presented across half-forward so well and is building his body and engine to hold down that position for a sustained period for Melbourne".
Shane Crawford, the 1999
Brownlow Medallist, noted he had improved that year and showed enough glimpses to predict he would be a top ten player in the competition in the next few years. A club post-season trip to
China saw Watts play in an exhibition match against Brisbane known as the Shanghai Showdown; played at
Jiangwan Stadium, Melbourne won the match by five points. in round 19, 2011. Entering the 2011 season, Watts added significant muscle weight during the off-season, which saw him play with greater impact in the forward line, as evidenced in strong performances during pre-season matches and the
NAB Cup. Forming a forward partnership with
Liam Jurrah, pressure was expected to ease off of Watts who was still seen as a developing player. He started the home and away season slowly, struggling to make an impact during matches, and during the round three and four wins against Brisbane and respectively, he was the substitute in both matches—substituted off in round three and starting substitute in round four—to finish with six disposals in each of the matches. Head of football writer at the
Herald Sun,
Mark Robinson described him as an "almost player" who "almost took the mark, almost won the ball, [and] almost changed the game"; in addition, 1987 premiership coach,
Robert Walls, noted he was "floundering". With the club having their first bye of the season the next week, Watts returned from the break with a turnaround in form; named in Melbourne's best players in the fifty-four point loss to West Coast at
Patersons Stadium in round six, he was praised for his decision making and was one of teams' positive sparks according to
The Age reporter, Simon White. He continued his good form and during the round ten loss against Carlton, he was entrusted with a new role in defence as the
loose man; his new role was partly to help him gain confidence by having more disposals and to help with his forward development. After a few weeks of playing in both the forward line and off of half-back, he played as a forward for the entire round thirteen match against in the eighty-nine point win at the MCG; he recorded twenty-four disposals and a then-career high three goals. He backed this up the next week by kicking three goals and finished with nineteen disposals—eleven of which were contested—four marks and four tackles in the twenty-seven point win against at the MCG; he earned his first
Brownlow Medal votes in his career, receiving one vote, meaning he was the third best player on the ground as adjudged by the
field umpires. Dean Bailey acknowledged after the match that Watts had had a consistent season to that point and then-teammate,
Colin Sylvia, said his consistency was imperative for his development and he had established himself as an AFL footballer. A drop in Melbourne's performances saw Watts return to playing parts of games in the back line; the week after the club suffered a 186-point loss to at
Skilled Stadium in round nineteen—the second heaviest defeat in VFL/AFL history which ultimately cost Dean Bailey his job—caretaker coach,
Todd Viney, praised Watts for his performance in defence, stating he "really stood up" and "his work-rate was excellent" in the seventy-six point loss to Carlton. Playing every match for the year, his season was noted for his continual improvement, which was evident in his ninth-place finish in the club
best and fairest count.
2012–2013: Playing as a defender and inconsistencies With the off-season acquisition of
Mitch Clark in the
2011 trade period, who was projected to be the number one forward in the team, the forward load was expected to be relieved off of Watts, who new coach,
Mark Neeld, stated would play primarily as a forward alongside Clark, rather than as both a forward and back as was the case the previous season. He struggled for form during the
2012 NAB Cup where he had just three combined possessions in the first two matches against Brisbane and Gold Coast, before he was substituted out of the match against Collingwood the next week where he managed just seven disposals, which drew the ire of former Collingwood coach,
Mick Malthouse, who said he lacked ambition when playing. He was subsequently omitted for the final pre-season match against Port Adelaide. After having an "impressive performance" playing for the Casey Scorpions in the VFL the week before the first round of the AFL season, Watts was named in the round one team for the match against Brisbane at the MCG. Struggling in the forward-line during pre-season matches, he instead started the match playing on the
wing and finished with seventeen disposals. Playing the first five matches for the season, he struggled for consistency and was subsequently dropped for the round six match against Geelong at
Simonds Stadium. With Neeld claiming Watts "had a few things [he needed] to work on", he played on the wing in the VFL where he kicked four goals and recorded twenty disposals and nine marks in the forty-six point win against in round seven. He stayed in the reserves the next week for the fifty-two point win against the and collected twenty-five disposals. His performances in the VFL saw him recalled to the senior side for the 101-point loss against at the
Sydney Cricket Ground in round eight; he played the match as the loose man in defence and recorded a career-high thirty-four disposals, in addition to eleven marks, eight rebound-50s and fourteen intercept possessions, the second most by any player that season to that point. Watts maintained a spot in defence and was praised for his efforts there by the media; in the three-week period following his return to the AFL side, he ranked first in the league for intercept marks and intercept possessions, and second in rebound-50s. He played particularly well in the six point win against the second-placed team, Essendon, in round ten where he recorded twenty-four disposals, seven marks, seven rebound-50s and four tackles to earn three Brownlow votes, thereby being adjudged the best player on the ground by the field umpires. Three weeks later, he played his fiftieth AFL match in the seventy-eight point win against at the MCG in round thirteen. After playing every match from rounds eight to fifteen, he was forced to miss five weeks of football due to an ankle injury; he returned for the twenty-five point win against Greater Western Sydney at
Manuka Oval in round twenty-one, to play the remainder of the season and finish with fifteen games in total. former Melbourne player,
David Schwarz, said prior to the commencement of the season that Watts would flourish in defence and that he would ultimately become a consistent player. The opening round loss to Port Adelaide by seventy-nine points at the MCG where he managed just seven disposals saw the players booed by Melbourne fans as they left the field; things did not become easier the next week when the club lost to Essendon by 148-points at the MCG, a game in which he was substituted out and was jeered by the crowd when this was announced. His poor to start to the season led to him being dropped for the round three match against West Coast at the MCG; instead of playing for Casey in the VFL, he did not play any football for the weekend. Despite not playing and football for the week, he was recalled to the senior side for the forty-one point win against Greater Western Sydney at the MCG in round four. Watts returned to the forward line the next week in the twenty-eight point loss to Brisbane at the Gabba in round five where he kicked two goals and was named in Melbourne's best players. This was his last match before straining his hamstring and subsequently missing three weeks of football; he returned for the ninety point loss against Fremantle at Patersons Stadium in round nine. In the lead up to the match, reports emerged that he was unhappy at Melbourne due to the club's misfortunes and that he would seek a trade away from the club with Fremantle being a possible destination. After the sacking of Mark Neeld in mid-June, Watts stated he wanted to remain at the club, however, he put contract negotiations on hold at the end of July and stated he would not decide on whether he would re-sign with the club until a new senior coach was appointed. Interim coach,
Neil Craig, opted to use Watts in a forward role and in Craig's second match in charge, he kicked a career-high four goals in the three point win over the at the MCG in round fourteen. In addition, he took a match-saving mark in defence and was awarded three Brownlow votes by the field umpires. His form improved under Craig, and Watts admitted he was not a fan of Neeld's hard-line coaching style, which was one of the reasons behind his poor form during Neeld's tenure. In the final round match against the Western Bulldogs at Etihad Stadium, he kicked an equal career-high four goals and in the eleven matches Neil Craig coached, Watts kicked eighteen goals.
2014–2017: Return to forward line and fulfilling potential With the arrival of new coach, Paul Roos, Watts was assigned a new role in the midfield; after having a strong pre-season, Watts was predicted to play an
on-ball role heading into the
2014 NAB Challenge. In the opening round match against at Etihad Stadium, he played primarily in the midfield and was named in Melbourne's best players; his new role saw him collect twenty-seven disposals and play with "confidence and flair" according to
AFL Media reporter, Peter Ryan, who also claimed Watts "[looked] set for a big year". With not one of Melbourne's three big forwards available to play in the early rounds of the year, he was forced to spend more time in the forward line than initially intended. However, Roos said Watts would not revert to his former role as a permanent forward and would instead spend time in the midfield. After a promising performance in round one, Watts played inconsistently the next few matches and played with a lack of intensity, according to former Richmond and Western Bulldogs forward,
Nathan Brown. Pressure mounted on him with the media debating whether he should be dropped for the round seven match against at the
Adelaide Oval. Roos defended his position and said Watts would maintain his position in the side, and that he could not understand the public's fixation with Watts and his form. He turned his form around in the seventeen point win against Richmond at the MCG in round nine where he kicked three goals and recorded a career-high eleven marks; he was pivotal in the win and settled into a mid-forward role for the rest of the year. Watts played every match during the year he could not escape the disapproval of the media. Former player and
The Age journalist, Matthew Lloyd, described his season as "disappointing", former Melbourne player and
SEN reporter, David Schwarz, noted he was "treading water" and said that his season had been "underwhelming", and
Leigh Matthews and Lloyd questioned his commitment to the sport. Although his season received mixed reviews, he finished inside the top ten of Melbourne's best and fairest count for the second time in his career, finishing tenth overall. With the intention of playing the 2015 season in the forward line alongside
Jesse Hogan and
Chris Dawes, a groin injury hampered Watts' pre-season training for three months heading into the season. He had a strong start to the season recording seventeen disposals, seven marks and three goals in the club's twenty-six point win against Gold Coast at the MCG in round one and was named in Melbourne's best players by
AFL Media. After a buoyant start to the season, he quickly found himself facing negativity from the media after the round three loss to Adelaide at the Adelaide Oval where he dropped two marks in quick succession, with one leading to an Adelaide goal. Multiple media figures called for him to be dropped with David Schwarz stating he "might have to sit out a week" and
Dermott Brereton professing "you have to make a stand as to what your team stands for, and that means you can't bring him back in until you are convinced he will not do that again";
Jason Dunstall supplemented these statements by noting "he can't relapse into these kind of performances", adding "I don't like using the word, but he looked a little soft at times". Two weeks later, he played his 100th AFL match in the sixty-eight point loss to Fremantle at the MCG in round five, a game in which he managed just seven disposals; after his milestone match he was condemned by Matthew Lloyd on the
Nine Network's
Footy Classified, saying "he's been gifted 100 games of AFL football". In the thirty-eight point loss against Sydney at the MCG the next week, he started as the substitute with Paul Roos attempting to ease the burden on Watts, although Roos later admitted starting as the substitute probably increased pressure on Watts. The relentless pressure on Watts saw him omitted the next week for the round seven match against , although it initially appeared he was dropped by the coaching panel, it was later revealed by Paul Roos that Watts asked to be dropped so he could find form playing in the VFL. Leigh Matthews described Watts' decision to drop himself as a shock because it never happened in his twenty years of coaching and he found it difficult to take seriously. Recording twenty-four disposals, eight marks and a goal in the VFL, his performance was described as "solid" by
AFL Media journalist, Peter Ryan and he was recalled to the senior side after the one week in the VFL for the thirty-nine point win against the Western Bulldogs at the MCG. Watts' return to the AFL saw his form improve, particularly his average disposal count, which increased by six a match in the five weeks from rounds eight to twelve, compared with the first six weeks of the season; he credited the opportunity to play in the VFL as a key reason to his improved form and his mind frame was more "calm and relaxed" heading into matches. He continued his good form playing on both the wing and in the forward line and after his performance in the thirty-seven point win against Collingwood at the MCG in round eighteen where he recorded twenty-six disposals—eleven of which were contested—four marks and a goal,
Herald Sun journalist, Chris Vernuccio, stated he was starting to "fulfil his potential and silence the doubters" and
The Age journalist, Michael Gleeson, noted he may have finally "turned a corner". The next few weeks saw Melbourne suffer heavy defeats and as Melbourne's form diminished, so did Watts' and he was omitted from the side for the final round clash against Greater Western Sydney at Etihad Stadium. Watts finished the season playing twenty matches in total. Entering the 2016 season, Watts was in his final year of his contract and would be eligible for
free agency at the end of the season if he remained unsigned; before the start of the season, speculation began as to whether he would remain at the club beyond the year or instead explore his free agency options. His first match of the season—the two-point win against Greater Western Sydney at the MCG—was "superb" according to
The Age journalist Jon Pierik; he recorded eighteen disposals, ten marks and a goal in the last quarter to help the team turn a twenty-one point deficit into a two-point win. Compared with previous seasons where he would play particularly well in the first match and then lose form quickly, he maintained his good form beyond the first match, which he credited to the team's improved performances. Watts' positive form was especially apparent in the thirty-five point win against Collingwood at the MCG in round four where he recorded seventeen disposals, eight marks and an equal career-high four goals to receive the maximum three Brownlow votes. The head of football writer at the
Herald Sun, Mark Robinson, also attributed his consistency to stability in his position—whereas in previous years he was moved around the ground, even multiple times during a match—he was now used as a permanent forward playing alongside Jesse Hogan. With the late withdrawal of
Cameron Pedersen from the team in the sixty-three point victory over Brisbane at the MCG in round nine, Watts was forced to play as the back-up
ruckman, which further proved his versatility; the move surprised onlookers, but he was praised by the media, particularly by
Fox Sports Australia journalist, Sarah Olle, who noted his athleticism led to a "surprisingly good" result. Being in career best form according to the media, Watts signed a three-year contract extension in July, tying him to the club until the end of the 2019 season. A week after his contract extension was announced, Watts was crucial in the two-point win against Gold Coast at the MCG in round nineteen when he kicked the winning goal with two minutes left in the match, his third of the match, and took a goal-saving mark in defence with forty-four seconds left on the clock. He was labelled as "the difference" in the match by
Fox Sports Australia journalist, Anna Harrington, and Mark Robinson noted his match-winning performance showed great leadership, an area he had previously been criticised as lacking in. His performance in the match earned him two Brownlow votes to be recognised as the second best player on the ground by the field umpires. He played every match for the season and kicked a career-high thirty-eight goals, in addition to achieving career-highs in marks, inside-50s, marks inside-50, and goal assists. and he was named in the ''AFL Media's'' team of the week three times during the season.
2018–2020: Move to Port Adelaide Watts was traded to the
Port Adelaide Football Club during the
2017 trade period. In September 2020, Watts announced his retirement, effective immediately, on the eve of Port Adelaide's 2020 finals campaign. ==Playing style==