Chelsea boss Avram Grant has revealed that Frank Lampard has suffered a setback in his recovery from a thigh muscle problem.
The England midfielder has been out of action since suffering the problem in the 4-4 stalemate with Aston Villa on Boxing Day.
Lampard had been pencilled in for a return in Wednesday's Carling Cup semi-final second leg meeting with Everton, but now faces at least another two weeks on the sidelines.
"All I can say about his injury is that he is not available for the moment, but we hope he will be soon as possible," revealed Grant.
"It is a little bit more complicated than we thought but I think he will be back soon.
"He has torn his thigh muscle for a second time and I think it could be between days or two weeks from now."
Meanwhile, Grant has revealed that Shaun Wright-Phillips could be a surprise inclusion the squad to face the Toffees, despite picking up an ankle problem in Saturday's 1-0 win over Birmingham City.
"The good thing with these players is they like to play and even when they are not fit and 100 per cent, they are doing everything to play," he continued.
"Not all the players have been 100 per cent fit for the last few games but the squad is very short.
"Everybody including Shaun is doing everything they can to play, but it is good news he is out there."