He also found first-team appearances limited under player-manager Ruud Gullit during the 1996–97 season. However he made six appearances in the FA Cup and was one of three centre-backs – the others being Frank Leboeuf and Steve Clarke – to start in the 1997 final as they beat Middlesbrough 2–0 to lift the trophy. The following season, Sinclair played in the 1997 FA Charity Shield as Chelsea lost on penalties to Manchester United after he missed the opening penalty. On 9 August, he hit the headlines after celebrating a goal against Coventry City by dropping his pants; he later explained he did this in tribute to his newborn daughter. He went on to score for Chelsea in the League Cup final, again over Middlesbrough, in a 2–0 win. His first team chances were starting to become limited though, as new manager Gianluca Vialli built a new team, which consisted mostly of continental stars including centre-backs Frank Leboeuf and Marcel Desailly, whilst John Terry was coming through the youth-team. He missed the UEFA Cup Winners' Cup final victory over VfB Stuttgart due to a calf injury, though did make five appearances in the competition. Due to the injuries and competition for places the League Cup final against Middlesbrough actually proved to be his final appearance for the club.