Chelsea striker Diego Costa ruled out for 1 month with hamstring injury

Diego Costa will miss four weeks with a hamstring injury, Chelsea manager Jose Mourinho has confirmed.

The Spain striker aggravated a hamstring problem in last weekend's win over Stoke.

Costa was already certain to miss the games against Queens Park Rangers and Manchester United but had hoped to return in time for the clash against Arsenal on April 26.

But Mourinho says Costa will be fit enough to face the final four games of the season, starting with the clash against Crystal Palace on May 3.

'Only Diego is injured, everybody else is fine and ready,' Mourinho said during the club's pre-match press conference on Friday. '[John Obi] Mikel is ready. [Cesc] Fabregas with a mask, but ready too. No problems.

'We have eight matches to play, if he [Costa] plays four it's normal,' Mourinho said.

'If he plays three it's a little bit below what I'm expecting. If he plays five it's more than I'm expecting.'

Costa has a history of hamstring problems but Mourinho is refusing to let his focus shift from Sunday's game at Loftus Road.

Asked whether he was concerned about the former Atletico Madrid forward's latest injury, the Chelsea boss said: 'Not concerned. I'm concerned about the match on Sunday.

'At this moment I don't want to think of him (Costa) for two, three weeks.'

Credit: Sami Mokbel/SportsMail