He worked as a goalkeeping coach at Wigan Athletic, Derby County, Hartlepool United, Hull City and Aston Villa.
[5] Walsh was given a professional contract for the 1986–87 campaign, during which Ron Atkinson was sacked in favour of Alex Ferguson and made his First Division debut against Aston Villa on 13 December 1986.
[4] For a short time in the 1987–88 season, a 19-year-old Walsh was made first-choice goalkeeper after Gary Bailey retired due to injury and Chris Turner was dropped from the team.
[8][9][10] He began the 1988–89 season on loan at Scottish First Division club Airdrieonians, being described as "a real class act" by manager Gordon McQueen after keeping a clean sheet on his debut at Falkirk.
[11] He made an "uncharacteristic blunder" to concede in a 1–1 draw with Greenock Morton, though saw out his three-game spell at Broomfield Park with a clean sheet in a 3–0 win over Queen of the South.
[17] An ankle ligament injury suffered by Peter Schmeichel saw Walsh play the last three Premier League games as United were crowned English champions.
[18] Schmeichel did recover in time to play the 1994 FA Cup final, leaving Walsh to sit on the bench and then lift the trophy with his teammates following a 4–0 win over Chelsea.
In the League Cup campaign, Walsh played in the quarter-final victory over Liverpool,[22] but was not selected in the final squad against Leicester City, who beat Middlesbrough in a replay.
In the FA Cup run he played in the opening game of the campaign against Chester City,[23] but would not feature in the tournament again as his teammates went on to lose the final 2–0 to Chelsea.
Walsh signed for Bradford City on loan in October 1997, before manager Chris Kamara paid a £500,000 fee to make the transfer permanent.
[29][30] However, he struggled with injuries at Valley Parade and the administration afflicted club were unable to justify his high wages any longer, so he was released by Bradford manager Nicky Law at the end of the 2002–03 season.
[33] Upon hearing of the move, Wigan boss Steve Bruce said: "Gary has conducted himself very professionally throughout my short stay here and has behaved with integrity".