Frank Lampard today called on his Chelsea team-mates to become more prolific in front of goal after Didier Drogba was ruled out for at least six weeks.

The Ivory Coast striker will undergo a scan today after suffering suspected ligament damage to his right knee when stretching for Florent Malouda's cross during last night's 0-0 draw at Cluj in the Champions League.

The blow leaves Nicolas Anelka and Salomon Kalou as the club's only fit, recognised strikers.

Lampard and Drogba scored 35 goals between them last term and the Blues are now set to rely even more heavily on the England midfielder's finishing.

Lampard, who has netted five goals already this season, said: "If Didier is out for a while, we will just have to get by.

"We will have to pitch in with goals from all around the team, which we can do, though the situation is not ideal.

"Nicolas is a top-class striker, and we also have Salomon and young Franco di Santo. The experience is not really there, but I believe the quality is.

"Hearing about Didier was the bad news of the day because he is so important to us. He has been out before with a knee injury. We hope he can be back as soon as possible."

Drogba's injury is not the only worry for manager Luiz Felipe Scolari, who could be without eight first-team regulars for Sunday's Premier League game against Aston Villa.

Drogba joins fellow internationals Deco, Ricardo Carvalho, Michael Essien and Joe Cole on the sidelines, while left-back Ashley Cole missed last night's game due to a back problem, and defenders Alex and John Terry both picked up back injuries.

The one consolation for Scolari is that his team remain top of Group A after escaping with a point from Transylvania last night despite not playing at their best.

Petr Cech was forced to make a superb save late in the game to stop Cluj's Uruguayan full-back Alvaro Pereira snatching a winner for his side.

Cech's intervention means Chelsea extended their unbeaten run under Scolari to nine matches, and Lampard added: "Petr is the best keeper in the world. He makes those saves time and again."