Ballack has not played since limping off against Newcastle

The Blues lead 1-0 after the first leg but midfielder Ballack is likely to miss the rest of the season after having ankle surgery on Friday.

The 30-year-old picked up the injury in the early stages of Chelsea's goalless draw with Newcastle last weekend.

Defender Carvalho, 28, sustained a knee problem against Bolton on Saturday.

We lost at Liverpool in the Premiership without Ricardo Carvalho and we go to Anfield again without him Chelsea boss Jose Mourinho

Ballack travelled to Munich for his operation, where he was treated by Germany's national team doctor Hans-Wilhelm Muller-Wohlfahrt.

He has scored eight goals for the Blues since joining on a free transfer from Bayern Munich last summer.

Carvalho was injured in the first half against Bolton and Chelsea manager Jose Mourinho said: "He is definitely out.

"He has injured his knee and it is a big blow for us. He has been our best defender this season - it is as simple as that.

"We lost at Liverpool in the Premiership without him and we go to Anfield again without him.