The west London side have been strongly linked with a move for England defender Cahill in recent weeks, particularly with Brazilian defender Alex likely to leave the club after his transfer request was accepted last month.

Whilst Villas-Boas has conceded he is in the market for defensive reinforcements, he suggested that Chelsea will not be looking to make many further additions in January.

Speaking after Monday's 1-1 draw with Fulham, Villas-Boas said: "We are trying to close the deal on a central defender, but I don’t think we will do much more than that."

A seven million pound switch for Cahill has been widely touted, and while Villas-Boas said talks had been held with the Trotters over a deal, he said there were other transfer targets other than the 25-year-old.

"We have had initial talks with Bolton, but this does not mean it has been concluded, and it does not mean that we are not looking at other players."