Manchester City Whelan started his career with
Manchester City joining from Irish feeder club
Cherry Orchard in 2001. He made a solitary appearance in the
UEFA Cup coming on as a substitute for
Paul Bosvelt against
Total Network Solutions in August 2003, before joining
Bury on a one-month loan the following month. After appearing in the Republic of Ireland's
2003 FIFA World Youth Championship campaign in November and December, he returned to Bury on another one-month loan on 24 December 2003. In total Whelan played 15 times on loan at Bury and caught the attentions of
Sheffield Wednesday manager
Chris Turner.
Sheffield Wednesday Whelan joined Sheffield Wednesday on a free transfer in the summer of 2004. He made his debut for Wednesday against
Huddersfield Town on 21 August and in his next match, a
League Cup tie against
Walsall, he provided
Lee Peacock with an assist and earned the praise from his manager. He scored his first goal for Wednesday in a 1–1 draw against Walsall in the league. His promising start to his Wednesday career took a knock as he was sent off in a League Cup tie against
Coventry City for "violent conduct". However, caretaker manager
Mark Smith criticised the referee's decision. Under new manager
Paul Sturrock the team managed to finish in 5th position in
2004–05 claiming a play-off place where they defeated
Brentford to reach the final. Whelan was voted "
man of the match" in the
League One play-off final against
Hartlepool United at the
Millennium Stadium in
Cardiff after scoring the match-winning third goal for Wednesday. After Wednesday won promotion to the
Championship, Whelan was trialled as captain by Paul Sturrock after regular captain
Lee Bullen was injured. Wednesday were able to avoid an instant return to the third tier in
2005–06 as they finished in 19th position, Whelan playing in 46 matches that season scoring once, which came in a 2–1 defeat against
Watford. In July 2006, Whelan was placed on the transfer list by Sturrock following increased competition for places in the Wednesday midfield after the arrival of
Wade Small,
Kenny Lunt and
Yoann Folly. He was subsequently removed from the transfer list by the following manager,
Brian Laws. Whelan repaid the faith shown in him with seven goals. He then went on to win a number of player of the year awards for the club's
2006–07 season. His performances led to manager Laws entering into contract negotiations with Whelan. Sheffield Wednesday rejected bids for Whelan from both
Burnley and
Plymouth Argyle in January 2008. However, a £500,000 bid from Stoke City was accepted on transfer deadline day.
Stoke City Whelan joined Stoke City on 30 January 2008 for £500,000 signing a three-and-a-half-year contract. He made his first Stoke City appearance in a Championship match against
Cardiff City on 2 February 2008 when he came on as a substitute in the 82nd minute for
Mamady Sidibé. Whelan made his first Stoke City league start the following match in a 4–2 victory against
Wolverhampton Wanderers. He scored his first goal for Stoke in a 2–1 home defeat to
Crystal Palace on 7 April 2008. Whelan played 14 times for Stoke City in the
2007–08 season as Stoke finished 2nd and were promoted to the
Premier League. in 2010 Whelan started the club's first match in the Premier League against
Bolton Wanderers. Whelan did not have a good match and as a result he did not feature much in the first team, only playing in League Cup fixtures and even
reserve matches. Despite this setback, Whelan was still a regular in the Irish national team. In December 2008 Whelan was being linked with a move away from the
Britannia Stadium but he revealed that he wanted to stay. Whelan did manage to force his way back into the first team and he became an important player in Stoke's successful fight for survival. Whelan scored a last minute
equaliser away against
Aston Villa on 1 March. Whelan signed a new four-year contract with Stoke on 15 September 2009. He scored his first goal of the
2009–10 season against
Tottenham Hotspur which earned Stoke a 1–0 victory. He also went on to score against Manchester City in a 1–1 draw with Whelan beating fellow Irish international
Shay Given.
Arsenal player
Aaron Ramsey praised Whelan for his support after Ramsey's suffered a leg break in a match between Stoke and Arsenal. He made his 100th appearance for Stoke in a 2–0 win over
Everton on 1 January 2011. After drifting in and out the starting eleven for most of the
2010–11 season Whelan made a return in March and played a key role in Stoke's run to their first
FA Cup Final. Whelan reached a century of league appearances for the club on 8 May 2011 against Arsenal. Whelan played in the
2011 FA Cup Final as Stoke lost 1–0 to his old club Manchester City. Whelan scored a rare goal for Stoke against
FC Thun in the
UEFA Europa League in August 2011. In a match against Bolton Wanderers referee
Howard Webb awarded an indirect free-kick inside the penalty area for a back-pass against Whelan after two minutes.
Kevin Davies scored from the quickly-taken restart to put Bolton ahead. Stoke chairman
Peter Coates criticised Webb's controversial decision to penalise Whelan. He scored his first league goal for more than 18 months against
Blackburn Rovers in November 2011. In January 2012, manager
Tony Pulis confirmed that he wanted Whelan to sign a new contract stating "Every time you ask Glenn to step up to that next level, he does it. He's a good lad, very single-minded. He's got that Celtic blood in him and the determination to prove people wrong – including myself at times". Whelan signed a new three-and-a-half-year contract on 11 January 2012 and said "I am loving life at the moment and things are going really well, so I am absolutely delighted to commit my long-term future to the club". In March 2012, Whelan made his 37th international appearance for the
Republic of Ireland, with all of his caps coming whilst at Stoke he surpassed
Gordon Banks' record becoming Stoke's most capped player. In the summer of 2012, Stoke signed midfielders
Charlie Adam and
Steven Nzonzi and Whelan's place in the side came under threat but he 'lifted his game' and retained his place for
2012–13 season. He avoided a ban after a 'two footed' tacked on Manchester City's
Javi García in the
FA Cup. Whelan played 34 times in 2012–13 as Stoke finished in 13th position. At the end of the 2012–13 season Tony Pulis was replaced by
Mark Hughes and Whelan stated that he hopes the change in style of play will help the team score more goals. Whelan initially had to fight for his place under Hughes at the start of the
2013–14 season but he soon became a regular in the side again. Whelan became a vital member of the team under Hughes and he made 36 appearances as Stoke finished in 9th position. Whelan retained his place in the side at the start of the
2014–15 season before he was ruled out of six weeks suffered a fractured leg whilst on international duty with Ireland in October 2014. He returned to the side in December 2014 after successfully recovering from his injury. Whelan signed a two-year contract extension in January 2015. In February 2015, Following an injury to captain
Ryan Shawcross, Whelan acted as stand-in captain and after a woeful 4–1 defeat against Blackburn Rovers in the FA Cup Whelan had a dressing room rant at his teammates. Whelan played 30 times for Stoke in 2014–15 as the Potters finished in 9th position for a second season running and they ended the campaign with a 6–1 victory against
Liverpool. His performances during the campaign earn him the praise of teammates Adam and Shawcross who both described Whelan as the teams 'unsung-hero'. Whelan was again a key figure under Hughes in
2015–16, making 42 appearances as Stoke again finished in 9th position. He made his 300th appearance for Stoke on 12 March 2016 against
Southampton, however he was not to be on the winning team as Stoke lost 2–1 at home. At the end of the campaign, Whelan admitted that he was disappointed that the team did not finish higher in the table. Prior to the start of the
2016–17 season, Whelan signed a one-year contract extension in July 2016, which ties him to Stoke until the summer of 2018. Whelan played 31 times in 2016–17, as Stoke finished in 13th position. Whelan gave an honest assessment of Stoke's campaign following a 2–2 away at
AFC Bournemouth on 6 May 2017. "We're disappointed, being twice up away from home especially to a team like Bournemouth and giving away two sloppy goals pretty much sums up our season I think".
Aston Villa Whelan joined Aston Villa
on 20 July 2017 on a two-year contract for a fee of £1 million. He scored his first goal for Aston Villa in a 4–2 win at Sheffield Wednesday on 24 February 2018. Whelan played 35 times in
2017–18 helping Villa reach the
2018 EFL Championship play-off final where they lost 1–0 to
Fulham.
The following season Whelan missed a 97th-minute penalty in a 3-3 draw home to
Preston. A cabbage was thrown at manager Steve Bruce who was subsequently sacked in favour of
Dean Smith. Whelan made 38 appearances as Villa again managed to reach
the play-off final this time beating
Derby County 2–1. At the end of the campaign Whelan's contract was not renewed by Smith.
Heart of Midlothian On 14 August 2019, Whelan joined
Scottish Premiership side
Heart of Midlothian on a one-year contract. He left the club in January 2020, after new manager
Daniel Stendel had dropped him from the team. Whelan subsequently criticised Hearts, saying that he felt like he had been "thrown under a bus" by the club and described the way they handled his departure as "amateurish". Conversely, it was later revealed that Whelan had made little or no effort to become involved in the club, and – in the words of journalist Tom English – 'club, players and fans alike were unconvinced by the level of commitment the Ireland international showed towards the club ... [and] not one person is sorry to see him go. Not one.
Fleetwood Town Whelan signed a short-term deal with
League One club
Fleetwood Town on 24 January 2020, joining until the end of the season.
Bristol Rovers On 4 September 2021, Whelan joined recently relegated
League Two club
Bristol Rovers on a one-year deal, linking up with former Fleetwood manager
Joey Barton having trained with the club for part of pre-season. On 11 September 2021, Whelan made his debut for the club playing the entirety of a 1–0 away defeat at
Hartlepool United. On 13 November 2021, Whelan was sent off after receiving two bookings as Rovers held on to beat
Northampton Town, a first sending-off since 2013. The season ended with Whelan securing a fourth career promotion, a 7–0 victory on the final day of the season moving Rovers into the final automatic promotion place, overtaking Northampton Town on goals scored having finished on the same points with the same goal difference. but he returned to Rovers just a few weeks later on 29 July 2022 in the role of first-team coach, also being registered as a player if he were to be required. Whelan made his final appearance of his career on the final day of the
2022–23 season in a 3–2 defeat to Bolton Wanderers. Having been brought on as a substitute, he himself was later substituted to a standing ovation at the
Memorial Stadium. He continued on at the club in the role of a full-time coach. ==International career==