 He was named in the PFA Second division team of the year for the 1993/94 season before transferring to Birmingham City in 1995.Castle joined Peterborough United on a free transfer as player-coach for the 1997–98 season, and over the next three seasons he played 122 senior matches and scored 20 goals winning the play-off final at Wembley in his final game.He moved to Leyton Orient on a free for 2000/01.