The 2001-02 campaign was the first full season under Italian manager Claudio Ranieri, who had replaced his compatriot Gianluca Vialli after five matches of the previous season. He made his first signing in the shape of French defender William Gallas for £6.2 million from Olympique Marseille, before signing Frank Lampard from West Ham United for £11 million on 14 June. Lampard went on to become Chelsea's highest goal scorer of all time. The signing of Lampard allowed Chelsea to part company with their captain Dennis Wise, who ended his successful 12-season spell at the club by joining Leicester City for £1.6 million. The third and final signing of the window was of French midfielder and 1998 FIFA World Cup winner Emmanuel Petit, who joined from FC Barcelona for £7.5 million on 26 June.

Chelsea players encountered controversy in the second round of the UEFA Cup, when they were due to face Hapoel Tel Aviv on 18 October 2001. Six Chelsea first-team players - Albert Ferrer, William Gallas, Emmanuel Petit, Graeme Le Saux, Eidur Gudjohnsen and captain Marcel Desailly - did not fly to Israel due to fears since the September 11 attacks in the previous month and recent Palestinian insurgency. Chelsea lost the match 2-0, with Desailly's replacement, the Ugandan teenager Joel Kitamirike, making mistakes in his only match for Chelsea. The six players returned for the second leg at Stamford Bridge, but a 1-1 draw saw Chelsea eliminated by an underdog for the second consecutive season.

...
Wikipedia