Blues boss Andre Villas-Boas on Friday revealed the parties were "miles apart" in their negotiations over personal terms after a £7million fee was agreed with Wanderers. Villas-Boas would not go into details about the impasse with Cahill - although one issue is understood to be the player's salary - or whether Chelsea had made a take-it-or-leave-it offer.
The Portuguese was nevertheless hopeful of a positive outcome, saying: "I think we can sort it out - it should be no problem. It's in my chief executive's hands at the moment. It's an ongoing conversation."
He added: "We'll have to wait for the best outcome. The best outcome for us is for the player to join us."
However, Villas-Boas warned Chelsea would turn elsewhere if an agreement could not be reached.
"We will continue to monitor this situation as we continue to monitor the other targets for this position," he said.
England star Cahill is not short of admirers, with Arsenal seeing a bid rejected for him in the summer and Tottenham also coming close to landing the defender. Spurs retain an interest and may choose to gazump Chelsea, as they did when signing Steven Pienaar from Everton in January.
Villas-Boas had no doubt about Cahill's qualities, despite Bolton's current struggles in the Barclays Premier League.
He said: "I think his technical attributes are immense. His pace is fantastic as well. There are weaknesses. But they're also related to the collective organisation of Bolton.
"He's a player who has been playing magnificently well at international level, normally alongside John Terry, and he can add to this squad or any squad in the Premier League. He can make this jump."
Source: PA
Source: PA