The 26-year-old was picked for the Lions' historic 2-1 series win over Australia in the summer but his involvement was ended when he suffered an ankle injury against Western Force.
The Irish prop underwent surgery following the tour and again in December but, despite missing the match with Munster, director of rugby Matt O'Connor believes he will be fit to play some part against Toulon.
"Cian was really close to playing and I'd be very surprised if he doesn't take to the field next week," said O'Connor, whose side beat Munster 22-18.
"We had to work incredibly hard; they defended very, very well in the first half.
"They got some reward at scrum time and at 9-0 it's looking like a pretty average evening.
"But the boys clawed their way back into it and the second-half performance was fantastic.
"But thankfully we got the rub of the green, we kicked a couple of penalties and we were pretty happy at half-time with where we had been relative to the score early and I thought the second half was a good performance."