Chelsea are still waiting for confirmation of the injury suffered by Cesc Fabregas, who had to be replaced midway through their Capital One Cup semi-final against Liverpool at Stamford Bridge.

Jose Mourinho's men went on to win the game 1-0 at extra time through a header from defender Branislav Ivanovic but the Spaniard's injury is likely to put their match against Manchester City into jeopardy next weekend.

In a crucial six pointer to decide the Premier League title, a loss for Chelsea will constrict their lead at the top to only two points, while a win would see them go eight points clear, in what is ostensibly an unassailable lead.

Fabregas, who has 15 assists this season, is an injury concern. Chelsea's chances of closing the gates on City will be reduced should he not be available. Mourinho said that the player reported a tight hamstring, but refused to comment on the extent of the damage.

"Fabregas reported a tight hamstring. He said he wasn't yet injured but that he would be soon if he continued," Chelsea boss Jose Mourinho said.

Ivanovic and Felipe Luis are also doubtful for the game with both suffering from a calf and foot problem respectively.

Meanwhile, talk of Diego Costa getting a retrospective ban is making the rounds for his reported stamp on Emre Can. However, Mourinho was quick to come to the defence of the striker, stating that the player was not in the wrong and it was the campaign against his side that was initiating such drama over nothing.

"He goes to the ball, he chases it, the opponent goes to the floor and he puts his foot there when he is looking at the ball," Mourinho said.

"I don't know what you understand by a stamp. Maybe you are already influenced by the campaign on the television with certain pundits saying Costa has committed a crime — the guy who says that must be nuts.

"It is a great campaign. We know how much that pundit loves Chelsea. You are a manager, on the bench, and these guys have a good seat, earning a lot of money, no pressure.

"They are never wrong, they have to be fair and they have to be honest," he added.