Nottingham Forest 2014–15 season Walker made his professional debut for
Nottingham Forest in the
Championship as a
substitute for
Chris Burke in the 92nd minute of a 2–0 win over
Rotherham United on 18 March 2015. Walker's first professional goal followed on 7 April in a 2–2 draw with
Brentford at
Griffin Park after he entered the game as a first-half substitute, on only his fourth first-team appearance. He signed a four-year
contract with Forest in June 2015.
2015–16 season Owing much to a shortage of strikers and
manager Dougie Freedman's willingness to give youth an opportunity, Walker played some games at the beginning of Forest's
2015–16 season. This included a start in the
League Cup, a 4–3 defeat by
Walsall at the
City Ground on 11 August; a game in which he scored his second goal in professional football. On 24 March, Walker joined
League One club
Burton Albion on
loan until the end of the
2015–16 season, where he would link-up with former Forest striker and Burton manager
Nigel Clough. Walker made his Burton debut four days later as a
half-time substitute in a 2–0 defeat at
Millwall. In 'The Brewers' following game on 2 April, he came off the bench to score an injury-time
equaliser in a 1–1 draw with
Bury at the
Pirelli Stadium. He returned to Forest at the end of the season having made six appearances for Burton Albion, scoring one goal.
2016–17 season In August 2016, new Forest manager
Philippe Montanier stated that he could not assess Walker due to an injury that left him unable to play a part in pre-season. On 31 August, Walker signed on loan with
EFL League Two side
Stevenage for the remainder of the
2016–17 season. He made his debut in a 6–1 win over
Hartlepool United at
Broadhall Way on 2 September; he scored a brace in the match, the first of which was an
overhead kick from close range – this performance earned him a place on the EFL team of the week. On 4 October, Walker scored on his debut in the
EFL Trophy in a 2–2 draw with
Brighton & Hove Albion's U-23 side. Having scored four goals in his first six games for 'The Boro', Walker missed a home game against
Plymouth Argyle on 8 October after picking up a "freak injury" in training. He eventually made his return from injury as a substitute in a 4–2 home defeat to
Colchester United on 31 December. Speaking after the match, manager
Darren Sarll admitted that he "forgot just how good" Walker was. Walker's loan spell with Stevenage ended earlier than planned, as Forest recalled the player on 13 January intending to secure him with a loan move to a League One club. He scored the opening goal on his debut with a "superb strike" for 'The Valiants', before also going on to win a
penalty in a 2–2 draw with
Bury at
Vale Park on 20 January. Walker's poor luck with injuries continued, however, as he sustained a
knee ligament injury the following month which
caretaker manager Michael Brown said would keep him out of action for the rest of the season.
2017–18 season Ahead of the
2017–18 season, Forest manager
Mark Warburton, who had been appointed as Montanier's permanent successor in March 2017, suggested that Walker would be involved with the first-team, claiming that he had "benefited from being in and around the first team squad here this summer" and that "other players need to go out on loan". On 23 August, Walker came off the bench to score the winning goal in
extra time of a 3–2 victory over
Newcastle United at
St James' Park in the second round of the EFL Cup. After the game Warburton confirmed in a post-match interview that Walker would remain at Forest for the season. He said: "We've had a host of clubs queuing up for Tyler Walker's services but he'll stay with us because of the reasons you've seen tonight. He's worked tirelessly to recover from injury, had a brilliant pre-season and that resulted in the quality of performance you've seen this evening." On 4 November, he scored the first brace of his senior career in a 4–0 home win over
Queens Park Rangers, earning himself a mention in the EFL team of the week. On 28 November, Walker signed a new contract at Forest, due to expire in 2021. On 31 January 2018, Walker joined fellow Championship side
Bolton Wanderers on loan for the rest of the
2017–18 season. He made his Wanderers début in their 1–0 victory over
Bristol City, starting the match and lasting 58 minutes before being substituted; he was replaced by fellow Forest loanee
Zach Clough. However, he featured just five times for the "Trotters" as manager
Phil Parkinson instead demoted both Walker and Clough to playing for the
youth team.
2018–19 season On 29 June 2018, Walker joined League Two side
Mansfield Town on a season-long loan. On 4 August, he scored 12 minutes into his debut for the "Stags" in a 3–0 win over
Newport County at
Field Mill. He scored a first-half
hat-trick ten days later as Mansfield recorded a 6–1 home victory over
Accrington Stanley in the first round of the
EFL Cup; manager
David Flitcroft said that Walker was "pure class". He scored his 15th goal of the season during a 2–1 Boxing day victory over
Bury, taking Mansfield into the automatic
promotion places. His scoring tally resulted in speculation that Forest manager
Aitor Karanka would recall him in the January
transfer window. He was named on League Two's
PFA Team of the Year for the
2018–19 campaign, alongside Mansfield teammate
Krystian Pearce. He was named as
man of the match in the
play-off semi-final first-leg against
Newport County, but had his penalty saved in the shootout at the end of the second leg as Mansfield were eliminated.
2019–20 season On 2 August 2019, Walker joined League One side
Lincoln City on loan for the
2019–20 season. Manager
Danny Cowley said that "he's been on our wish list forever." After scoring 16 goals in 34 games for the "Imps", Walker was recalled to parent club Nottingham Forest by manager
Sabri Lamouchi on 30 January. He was then restricted to appearances from the substitutes bench at Forest, though did manage to score against league leaders
Leeds United on 8 February. He was cited as being the "next in line" by star striker
Lewis Grabban.
Coventry City On 28 August 2020, Walker joined newly promoted EFL Championship side
Coventry City on a three-year deal for an undisclosed fee. Manager
Mark Robins said he had monitored Walker for some years. He scored on his debut for Coventry in a 1–0 EFL Cup win at
Milton Keynes Dons on 5 September. He scored his first league goal for Coventry in a 3–2 defeat at
Watford on 7 November. He scored eight goals from 33 appearances in the
2020–21 season. Walker suffered a
tore anterior cruciate ligament (ACL) in October 2022. He made 19 appearances in the
2022–23 campaign, scoring one goal, and was released upon the expiry of his contract.
Portsmouth (loan) On 18 January 2022, Walker joined League One side
Portsmouth on loan until the end of the
2021–22 season after being signed by former Lincoln manager Danny Cowley. The loan spell was largely disappointing as he scored just one goal in nine starts and six substitute appearances for "Pompey" and was an unused substitute in the final six matches of the campaign despite being the highest paid player at
Fratton Park. Jordan Cross of the
Portsmouth News wrote that "Walker will go down as one of the worst and most expensive loan mistakes seen at Pompey in recent years".
Lincoln City On 12 July 2023, he joined
Lincoln City permanently on a
free transfer on a two-year deal;
Jez George, the club's
director of football, said that "this is a football decision" from Walker that did not risk "compromising our wage structure".
Head coach Mark Kennedy said that "with
Ben House, he gives us two outstanding centre forwards". On 5 August 2023, he made his permanent Lincoln City debut, starting against
Bolton Wanderers. However, just five games later he was ruled out for eight weeks with a
hamstring injury. On 7 December, it was confirmed that Walker suffered a recurrence of the hamstring problem and was likely to miss the rest of the
2023–24 season.
Wealdstone (loan) On 14 March 2025, Walker joined
Wealdstone of the
National League on loan for the remainder of the
2024–25 season as Lincoln's director of football
Jez George allowed him to opportunity to find regular football following his recovery from a series of injuries. His wages were funded by the Wealdstone FC Supporters Club. He was released upon the expiry of his contract after returning to Lincoln.
Barrow On 30 June 2025, Walker agreed a one-year deal – with the option of a further year – with League Two club
Barrow. He made his debut on the opening day of the season, coming off the bench in a 1–0 defeat against
Chesterfield. He scored his first goal in the EFL in two years by opening the scoring in a 2–1 win against
Notts County on 16 August. ==International career==