"Hernan is a Chelsea player, but he has never hidden the fact that his wish is to return to Italy," Mourinho was quoted as saying by Sky Sports Network.

Crespo, a former Parma, Lazio and Inter star, joined the blues in 2003, but he struggled with injuries and couldn’t adjust to English football, scoring only ten goals in his first season.

The Argentinean international then moved on loan to AC Milan where he enjoyed a successful season before returning to Stamford Bridge where he scored 13 goals this season mainly off the bench.

"He has always been very correct, I have allowed him to go and from Monday he will be with the Argentina squad," Mourinho added.

Mourinho will be looking to replace Crespo which grows more speculations that either Barcelona's Samuel Eto'o or Milan's Andrei Shevchenko could be on their way to club.

"Ballack should sign, we are also looking for a forward, and it's normal that the names of Shevchenko and Eto'o are mentioned, we will see what happens," Mourinho said.