Defender Ricardo Carvalho insists Chelsea's recent form will have sent a message of intent to their title rivals.

The Portugal centre-half also maintained Chelsea's performances during January proved they could cope without their African Nations Cup quartet of Michael Essien, Didier Drogba, Salomon Kalou and John Mikel Obi.

Drogba and Kalou will be back in the squad for tomorrow's trip to Burnley in the Barclays Premier League as Chelsea look to heap more pressure on rivals Manchester United and Arsenal.

However, Carvalho is well aware playing well will mean nothing unless the Blues can win some silverware under new coach Carlo Ancelotti.

"We are playing well but in the end you have to win trophies," said Carvalho. "Everyone knows how important the league is for us and we want to be at the top and we want to stay there until the end.

"The message to the other teams now is they have to be worried about us because we have got great players here and we are fit and wanting to play well and help the team to win the trophy.

"Everyone was speaking a bit too much that we could miss the Africans but we have a strong squad with players who want to play as well. They showed everyone that they have got quality to play.

"Now it is welcome to Didier and Salomon. They are important players and they are good to come back. In February there are a lot of games and they can help us."

Chelsea midfielder Frank Lampard insists team-mate Joe Cole has every chance of convincing England boss Fabio Capello that he is worth a place in his squad for the World Cup finals this summer.

Lampard helped put an end to Birmingham's 15-game unbeaten run on Wednesday night with two goals in a 3-0 victory but Cole again demonstrated he is almost back to his magical best by providing the first goal for Florent Malouda in the fifth minute.

Chelsea's victory over City put them one point clear of Manchester United at the top of the Barclays Premier League with United travelling to face Arsenal on Sunday.

But Cole, 28, who has yet to sign a new deal at Stamford Bridge, is battling to prove to Capello he is worth taking to South Africa.

His chances are far from certain because he has not played for England since he came back from his knee injury in September and his performances in a Chelsea shirt before Christmas were somewhat inconsistent.

But Cole is now on the brink of re-discovering his best form and Lampard believes he should be given a chance to demonstrate that when England take on Egypt in a friendly in five weeks.

It will be one of the last opportunities for him to impress with Capello having to name his 23-man squad for the World Cup in May.

"I hope Joe gets called up by England - he deserves it for the hard work he's put in," declared Lampard.

"The England manager knows how good a player he is, like everyone at Chelsea does. If Joe keeps playing the way he is for Chelsea, he will have a great chance.

"He's getting sharper and sharper. Joe's that one player who injects that bit of brilliance where he can beat a man out of nowhere.

"He had a very bad injury and people expected him to come straight back in but it's not possible. He has worked harder than anyone and now we're seeing the benefits of it. He's only going to get better."