Crespo had not actually played for Chelsea since the 2005/6 season after falling out of favour with Jose Mourinho.

The Argentinian spent the last two seasons on loan with Internazionale, having played for AC Milan in 2004/5.

Crespo was one of the first signings made by Claudio Ranieri after Roman Abramovich bought the club in 2003, scoring 12 goals in his opening campaign.

However, after Mourinho's arrival he was shipped out to Milan, playing and scoring in the Champions League final defeat to Liverpool in Istanbul.

A Chelsea statement read: "We thank Hernan for his efforts in a Chelsea shirt, and wish him well in the future."