The central defender, who is a contender for the World Cup squad, could now be pitched into Bolton's showdown with league leaders Manchester United at the Reebok Stadium on Saturday.
That would be Cahill's first senior appearance since January 30 as he has spent the last two months recovering from a blood clot that led to him undergoing surgery to remove a section of a rib.
Up for the battle: Gary Cahill has passed himself fit for United clash
'It came as a total shock to me and, at first, I feared the worst and thought it was going to be long term,' Cahill told the Bolton News.
'But I've come back a lot earlier and quicker than some people thought, and it's good to be back.'
After coming through 90 minutes in the reserves on Monday, Cahill added: 'You would have to ask the gaffer, but I'd like to think that's me finished in the reserves.
'I've proved I'm fit to play 90 minutes and that was a big thing, so this weekend I'm available for selection.'
Fellow defender Zat Knight, meanwhile, is convinced Bolton can put a spanner in the works of United's championship charge.
Zat's brave: Knight says Bolton can upset the Premier League champions
Wanderers head into the game on the back of an impressive recent home run that has seen them take 10 points from the last 12 at the Reebok Stadium where they have kept four successive clean sheets.
Towering centre-back Knight believes Bolton can build on that, despite facing a United side going for their fourth consecutive title.
'It's going to be a tough game, but our home form has served us well in the last few months,' said Knight.
'Anything you get against Manchester United is still a good result at home. 'On the road, it's hard, but any time you have a game at home then you expect to get something from it.'
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