Cahill played the full 90 minutes on Wednesday night, as the Blues defeated his ex-employers Bolton in the League Cup, and he will likely start in West London at the weekend.
Having started his career with Villa, making 28 appearances for their first-team following his progression through the academy system, the 28-year-old moved to the Trotters in 2008, becoming vice-captain in the course of playing 130 times.
A move to Chelsea beckoned in 2012, and the England international won the UEFA Champions League and the FA Cup after just six-months at his new club.
Having been in the line-up to face Bolton last night, Cahill admitted that it is a strange situation to face a former club, with ‘added emotion’ potentially ruining your personal game.
He told chelseafc.com: "Any player will tell you that when you’re playing against your old club there’s that added bit of emotion.
"You try not to let it affect you and play your normal game but I’m a professional and the most important thing is that we won the game. They made it tough for us but thankfully we won.”
Premier League action returns to Stamford Bridge this weekend, and up next for the Blues are Villa, who gave Cahill a ‘great time’ during his upbringing in the Second City.
"I had a great time at Villa, more than anything with the youth team," the central defender added.
"I owe a lot to them, they brought me through and I had a great time, so I’m looking forward to it.”
However, he has once again refused to bow to emotion, with the Villains enjoying a strong start to the season, having lost just one game.
"They’ve had a great start to the season, apart from their last result, so it’s going to be another tough test for us.
"It’s great to have a winning mentality, if you have a couple of sticky results it puts the pressure on going into games but at the moment we’re unbeaten, we’re going well and we should have confidence, especially playing in front of our own fans at Stamford Bridge."