Chelsea manager Claudio Ranieri bought Gallas from Marseille in 2001 for £6.2 million. He chose the number 13 shirt because it was his postcode back where he lived in Marseille. Under Ranieri, Gallas developed centre-back partnerships with Marcel Desailly and later with John Terry. His partnership with Terry included a run of 16 games without conceding a goal. He also played as a left-back at times. It was with Chelsea and under Ranieri where Gallas obtained his first international cap for France. Gallas made his debut as a substitute for John Terry against Newcastle United in August 2001. His first goal followed in the FA Cup against Tottenham Hotspur. Chelsea ended up reaching the 2002 FA Cup Final in which Gallas started, however they were defeated by Arsenal.