The Wales flanker suffered a torn hamstring in the second Test against Australia in Melbourne this summer, an injury which kept him out of the deciding fixture with the Wallabies.
An early recovery period of between 12 and 16 weeks was the initial prediction but with Warburton returning for this weekend's trip to Leinster, the 24-year-old is well ahead of schedule.
After the Blues' disappointing defeat to Zebre last Friday, Warburton's return is the perfect tonic for boss Phil Davies as he prepares his side for a visit to last year's champions.
"We've got Sam Warburton back in the team starting and we've made a few changes," Davies confirmed this afternoon.
"Some are through injury, some through necessity but it's a great challenge for us playing the champions at their home ground.
"If you can't look forward to that as a rugby player, there's something wrong with you."
The Blues have a poor record in Dublin and were comfortably beaten by Leinster at the RDS last season. But with Warburton and fellow Lions Leigh Halfpenny and Alex Cuthbert all set to start, Davies has a near full strength side available. Wales wing Harry Robinson is also set to return.
"Sam wanted to play. He him himself has done a phenomenal job, as have the medical department," Davies added.
"He's five weeks ahead of schedule and that's down to his diligence. He was knocking the door down to play which is fantastic. It's really exciting.
"It says a lot about our medical department. Sam is one of the most professional players you'll ever wish to meet. It's down to him and the doctors who have been working on him.
"We've got an anti-gravity treadmill and I know that's helped his cardio vascular fitness."
A trip to Leinster is not going to be an easy task, especially following the Blues' result against Zebre. Davies though, argues his side have put the defeat behind them.
He said: "We came in on Monday and all of us made our feelings know.
"We're striving to be successful but sometimes setbacks drive teams forwards and that's what we're doing this week.
"We've trained very well and built on the work as well as looking at where we can improve for a pretty uncompromising fixture this weekend."