A torn ankle ligament suffered in September means he has made just three appearances so far but the 27-year-old is in line for a return to action against Harlequins in the Heineken Cup this weekend.
He will have plenty of familiar faces from the summer alongside him, with fellow Lions Jonny Sexton, Dan Lydiate, and recent signing Mike Phillips also in the team.
A Welsh international for the last five years, Roberts got his first taste of Lions duties in the 2009 tour to South Africa.
And after succeeding at the second attempt in the summer, he is itching to replicate the experience on a domestic level at his new club.
"Racing are ambitious and so am I," said Roberts. "I want to win things and I want to be in form.
"Racing and Wales go together. I love being on rugby tours.
"That was how the Lions was - new blokes, different backdrops, brilliant. This is like a three-year tour.
"It is a real relief to get back into action. The upside is that it whets the appetite again, makes you desperate to get out there, picture in your mind's eye what it is like to win big matches again."