The Blues were confident of wrapping up the deal by the end of the week but that had not happened before the midday cut-off for Cahill to be registered for Saturday's Stamford Bridge clash.
It remained to be seen whether the Bolton defender would complete what has been a protracted move on Friday and become Chelsea manager Andre Villas-Boas' first January signing. If not, Wanderers boss Owen Coyle has already confirmed Cahill would be in contention for his current employers' trip to Manchester United.
An additional 24-hour delay would not necessarily be a bad thing for Chelsea, with Cahill undoubtedly strengthening a Bolton side they will be hoping take points off United on Saturday. But the more time that passes without an announcement, the more doubt is cast over whether the parties have been able to agree personal terms.
It is now more than a fortnight since Bolton accepted a £7million bid from Chelsea for their prize asset, who was in the final six months of his contract.
Negotiations immediately hit a snag when Blues boss Andre Villas-Boas revealed club and player were "miles apart" in terms of Cahill's salary.
Reports claimed the England international was demanding £100,000 per week, £30,000 more than Chelsea were willing to pay as they seek to reduce their overall wage budget in the era of Financial Fair Play.
There were also suggestions in midweek a compromise figure of £80,000 had been agreed but Cahill trained with Bolton on Thursday morning and there have since been reports Blues chief executive Ron Gourlay had travelled to the north west for further talks.
Villas-Boas was confident on Thursday of a positive outcome "this week" and refused to criticise Cahill or his representatives for the delay.
"It's part of negotiation," Villas-Boas said."I'm sure all parties are protecting their interests and we'll reach an agreement."
Source: PA
Source: PA