Didier Drogba admitted Chelsea could have done more against Olympiacos and says they will have to improve their game if they are to make it into the next round.

Drogba looked out of sorts against the Greeks in his first game for Chelsea since returning from the African Nations Cup.

Avram Grant now has a fully-fit squad to choose from for the first time since he took charge and the Ivory Coast striker admitted that "is a big problem for the manager" as he tries to settle on his best side.

Drogba said: "We had a difficult game and could have done better. The good thing is we have a second game at home and have to improve if we want to beat Olympiacos.

"I am looking forward to playing with Nicolas Anelka but I am just happy to be back and playing with my mates.

"I hope we can do great things but don't forget the other players. We have a big squad and I hope everyone will be committed and give everything for what we want to achieve."