Following retirement, Sealey was appointed first team goalkeeping coach at West Ham United, a position he was in when he died of a heart attack on 19 August 2001.

A year later, Luton reached the final again and he was able to keep goal this time in a 3–1 defeat to Nottingham Forest in which Sealey had a poor game, including fouling Steve Hodge to concede a penalty (converted by Nigel Clough).

He was named as goalkeeper for the 1990 FA Cup final replay against Crystal Palace after a poor display from Jim Leighton in the preceding 3–3 draw, and made several saves to help his side win 1–0.

He had several games on loan at Birmingham City during the opening weeks of the 1992–93 season before returning to Manchester United on a free transfer in January 1993, this time as Peter Schmeichel's understudy.

[8] At the end of the season he was given a free transfer and joined Blackpool, but within six months he had left Bloomfield Road and returned to the Premiership with boyhood heroes West Ham.

[3] Due to an injury crisis, Sealey made his Hammers debut as an outfield player, coming on as an attacking substitute against Arsenal in the autumn of 1995.

Upon his return to West Ham he was appointed as the club's goalkeeper coach, although he was still registered as a player during the 1999–00 season, taking him past his 42nd birthday in September 1999.