Andre Villas-Boas has admitted Chelsea's interest in Gary Cahill but insisted they had yet to make a bid for the Bolton defender.
Reports on Wednesday morning claimed Wanderers had accepted a £7million offer from the Blues for the England star, who has long been linked with a move to Stamford Bridge.
Cahill, who turned 26 on Monday, is out of contract in the summer and the January transfer window is the last chance for struggling Bolton to cash in on one of their prize assets.
Villas-Boas said: "We are aware of Gary's contractual situation.
"He's an interesting player for the club."
Chelsea are short of cover in central defence, with Alex having been banished from the first-team squad after handing in a transfer request.
Villas-Boas added: "You know that we have taken a decision this season regarding the central defenders, regarding Alex.
"We haven't decided yet what we are going to do with the Alex situation.
"We have to make the wisest decision, be it Alex, be it Cahill."
