The pair started together in midfield for the first time this season in Sunday's goalless draw with Liverpool.

Critics remain unconvinced that they can successfully play alongside each other, but the Germany captain has no such fears.

"Frank is a very good player and we need him," said Ballack.

"He has scored a lot of goals and it is not about him, me or anyone else in midfield. I have no problems playing with anybody and it is better to have a good player by your side than a bad one.

"I think we can put all the doubts to bed. We have played a lot of games together and it is not a problem."

Meanwhile, Lampard's future has again come under scrutiny with Serie A side Juventus the latest club to be linked with the England midfielder.

Renewed speculation in Italy suggest Juventus will bid for Lampard's services in the summer.

Juve boss Claudio Ranieri is a big fan of Lampard having signed him when he was in charge of Chelsea.

The player's long-term future at Chelsea remains in doubt as he has yet to agree a new deal at Stamford Bridge with talks on an extension to his current contract on hold until the end of the season.

Chelsea's squad has been boosted by the return of Michael Essien, Salomon Kalou and Didier Drogba from African Nations Cup duty.

The continued rehabilitation of captain John Terry and Andriy Shevchenko also bodes well for Avram Grant's side.

Terry is convinced he will be fit enough to return to first-team duty within a fortnight but there is still a lot of work to do before he take part in training with Grant's squad.

Kalou was a part of the Ivory Coast squad that eventually finished fourth in the tournament - losing out to Essien's Ghana in the third place play-off having been eliminated by eventual winners Egypt.

It was the 22-year-old's first major international tournament, and an experience he will not forget in a hurry.

"It was my first one so I really enjoyed it and it was a good tournament to play," said Kalou.

"It is always special playing for the national team, a special moment and time. It was a pity that we didn't win through to the final because we started really well, but that's football and we have to put it together and think about next time."

Kalou scored three goals in the tournament but managed to keep in touch with Chelsea's progress in England while he was away.

He added: "Every time Chelsea had a game we asked for the score and saw the game when we could.

"I saw a couple while I was out there against Tottenham and Wigan. The team did well, kept winning games, and now we are back I hope the team is stronger."