Born in Chorley, Lancashire, Unsworth began his career in the youth system at Everton. He made his first team debut in an away game at Tottenham Hotspur in April 1992. He made few appearances for the senior side until the appointment of Joe Royle as manager. Royle made Unsworth a regular member of the starting XI, and he was part of the 1995 FA Cup winning team. After 133 league and cup games over several impressive seasons at Everton, Unsworth transferred to West Ham United for the 1997–98 season. He made his West Ham debut on 23 August 1997 against his old club, Everton. After receiving an ovation from Everton fans, Unsworth was on the losing side as West Ham lost 2–1. After his family failed to settle in London and only one season and 41 games he asked for a move closer to his Merseyside home. Rather than moving back to Merseyside, he was signed by Birmingham-based club Aston Villa for £3 million but his family did not settle in Birmingham. After only a month, before the season had even begun, citing problems with the lengthy commute from his home, he returned to Everton who paid Villa the same £3 million West Ham had accepted only a few weeks before.