The Ireland centre only rejoined the squad on Thursday
Connacht head coach Pat Lam has made two changes from the starting XV that lined out for the win over Edinburgh three weeks ago for Saturday evening's clash with Leinster in the Sportsground.
Academy centre Peter Robb is handed his first Pro12 start and partners Bundee Aki in midfield. 21-year-old Robb made his Connacht debut in November in the Challenge Cup game away to Russian side Enisei-STM. The Leinster game will mark his tenth appearance in a Connacht jersey.
Niyi Adeolokun returns to the right wing after missing the Edinburgh game through injury and is the only other personnel change to the team. The half back pairing is once again made up of AJ MacGinty and Kieran Marmion, who made his Six Nations debut earlier this month.
The packs sees Ireland international Nathan White, who featured in all five 6 Nations games, pack down in the front row while 21-year-old Sean O'Brien from the Academy is again included in the back row with Jake Heenan and captain John Muldoon.
Internationals Robbie Henshaw - who only joined team training on Thursday - and Finlay Bealham are both named amongst the replacements. Frontrower Bealham who has featured in every Connacht game this season, is in line to make his 50th appearance.
Commenting on the upcoming game, head coach Pat Lam said:
"I have a lot of respect for who Leinster are and what they have achieved. There is a lot of quality right across the squad and I believe Leo (Cullen), in his first season as head coach, has done a tremendous job. Tomorrow, we are expecting a pretty physical and fired up opposition. As a team who have history of winning at this stage of the season, it's going to take a massive collective effort from us to come out on top.
"There's certainly a huge buzz around this game tomorrow and we're all really looking forward to it - it doesn't get much better than playing in front of a sold-out Sportsground. Staying focussed and chanelling that excitement and energy into our structures and systems will give us the best chance of getting the points on offer."
Connacht team and replacements to face Leinster:
(15-9): Tiernan O'Halloran, Niyi Adeolokun, Bundee Aki, Peter Robb, Matt Healy, AJ MacGinty, Kieran Marmion.
(1-8): Denis Buckley, Tom McCartney, Nathan White, Quinn Roux, Aly Muldowney, Sean O'Brien, Jake Heenan, John Muldoon (capt).
Replacements (16-23): Dave Heffernan, Ronan Loughney, Finlay Bealham, Andrew Browne, Eoin McKeon, Caolin Blade, Shane O'Leary, Robbie Henshaw.