Chelsea manager Andre Villas-Boas has revealed that he has yet to convince Didier Drogba to sign a fresh deal at Stamford Bridge as talks continue between the two parties.

The 33-year-old striker, who is scheduled to join up with the Ivory Coast national team for the African Cup of Nations next month, has been linked with a move away from the Blues after continually failing to commit to a new contract.

"We've had these talks before," said Villas-Boas. "Our interest is there and the agreement hasn't been done. January arrives and the player is free to start speaking to other people and he has this advantage but his integrity and his values are never in question, neither his professionalism.

"We have to reach an agreement. It's a two-way process and it's been ongoing for quite some time. We could have reached an agreement earlier but it wasn't the case and now January arrives for the player to consider his options.

"For me as a manager it's important to count on the player and person and I'm sure I can have it 100%."

Meanwhile, Chelsea are closing in on a swoop for Bolton Wanderers defender Gary Cahill after the two clubs agreed a fee for the England international.