Cahill and David Luiz both appeared to come through unscathed as they stepped up their comeback from hamstring injuries just four days before Saturday's showdown with Bayern Munich.
It was a huge boost for Chelsea, who were in danger of going into the Allianz Arena clash without any recognised senior centre-backs.
England defender Cahill, who suffered his injury during last month's epic semi-final second leg at Barcelona, said: "I'm just happy that it's healed quickly.
"We've worked really hard, all day, afternoons, and I'm fortunate enough to be back.
"Hopefully, I'll be fit, I will be fit, and hopefully I'll be out there if selected."
He added: "First full session with the boys after my injury, so nice to get back out there and get running around and kicking a ball about.
"There's some work to be done in two or three days now leading up to the game for me to get back into it.
"And if I need to do a little bit of other training, I'll do that.
Watch: Cahill and Luiz ready to face Bayern.. More Videos
"But, touch wood, there's no reaction from and I felt fine out there."
Cahill, who joined Chelsea from Bolton in January, admitted Saturday's game would be the biggest of his life.
"I think it's the biggest game for probably many of the boys," he added.
"We're under no illusions how big the game is.
"It's going to be a good night and, hopefully, it goes to plan."
Cahill was desperate to hear the famous Champions League music one more time this season.
"It's just like when the national anthem plays for England, isn't it?" he said.
"It is a sort of hairs-on-the-back-of-your-neck moment when you hear it and it gets you geed up and fired up for the game.
"But I don't think we'll need any of that for this game.
"Everyone knows how big the game is."
Luiz, who has not played for exactly a month, said: "I'm so happy to return to training and now I can help Chelsea in this final."
There had been concerns neither he nor Cahill would be match fit on Saturday but the latter said: "I've missed games but I don't think at this stage of the season you're going to lose too much fitness.
"It's not like I've been out for months, so it shouldn't matter too much."