Last weekend's 2-0 defeat at Liverpool left Chelsea in third spot in the Barclays Premier League, three points behind Rafael Benitez's team and five adrift of leaders Manchester United, who also have a game in hand.

Chelsea have only picked up one point from four games against their two main title rivals and Anelka admits that could cost them dear.

"The title hasn't yet been lost," he wrote in his weekly column for Lesdessousdusport.fr. "But it will be really hard now.

"Since the beginning of the season we have not succeeded in our matches against the big teams.

"Our rivals are as strong as us, we have to do more, in the battles, in technique.

"It's our duty to do better and to step up a gear. Against the big teams we have never been at the level of the real Chelsea."

Anelka also commented on Chelsea's latest signing, Ricardo Quaresma, who moved to Stamford Bridge on transfer deadline day on loan from Inter Milan until the end of the season.

"We have just welcomed Ricardo Quaresma," he continued. "I have done two training sessions with him.

"He is very skilful, intelligent. He will bring a lot to the team."