Chelsea have confirmed that Andriy Shevchenko needs to have surgery on his troublesome groin injury.
However, the Blues hope that the Ukrainian will return to action before the end of the season.
The injury forced Shevchenko to miss Tuesday's Champions League semi-final defeat at Liverpool.
A statement on the club's official website read: "The injury meant he missed the Liverpool match but we are hopeful he will be available between now and the end of the season."
Meanwhile, Hernan Crespo has reiterated his desire to stay in Italy insisting he has no intention of returning to Stamford Bridge.
The Argentina international is on a two-season loan spell with Internazionale, but Chelsea have the option to recall him after one year.
"Chelsea have until 31st May for asking me to return. Just with sending a fax," Crespo told the South American media.
"If they don't do that my loan at Inter gets renewed automatically.
"But if they want me to return we will have to have a conversation about that. That's why the less it is spoken about the better for me.
"At this moment Chelsea are totally concentrating on the next games of the Premiership so I don't think that they will be thinking of me but if they are they know what my opinion is."