The Newtownmountkennedy man will partner Devin Toner in the second row, fresh from his call-up to the Ireland squad earlier this week.
Isaac Boss joins Jonathan Sexton at half-back, with Eoin O'Malley lining up at centre with Fergus McFadden in a back-line which also includes Shane Horgan, Rob Kearney and Isa Nacewa.
Andrew Conway's good form, after the Ireland Under-20 winger scored a brace of tries in Leinster's opening round 33-28 British & Irish Cup win over Newport last Sunday, sees him take his place alongside fellow replacements Gordon D'Arcy, Nathan Hines and Eoin Reddan.
In all, Leinster coach Joe Schmidt has made four changes to his starting line-up. The combinations in the back-three, back row and front row remain intact.
Speaking ahead of Saturday's interprovincial derby, Schmidt said: "I'm expecting Connacht to really charge at us, particularly some of our exports (who are) there.
"There are some really good young guys who have gone there and are showing a fair bit of form - the likes of Jamie Hagan, Ian Keatley and Fionn Carr, just to name a few.
"I know that they'll be really motivated. I know that Connacht see themselves as the underdog and they're always highly motivated for these Leinster matches.
"I thought that our discipline was pretty good against Saracens, though we did struggle a bit in the last 20 minutes.
"Having had a good look at the video, we got some pretty tough calls against us in that last 20 minutes, so we have to try and maintain that discipline and improve upon it this week.
"I thought our defence was really good, so I think we'll be looking to put a few more attacking phases together."
He added: "Connacht could have, and maybe should have, beaten Ulster in the last Irish match-up that they had. With the quality of the start of the season that Ulster have had, it speaks volumes for what Eric (Elwood) has done there and is doing there currently.
"The confidence that they will bring to the game means that that there's no doubt that they will come very hard (at us) right from the start."
LEINSTER (v Connacht): Rob Kearney; Shane Horgan, Eoin O'Malley, Fergus McFadden, Isa Nacewa; Jonathan Sexton, Isaac Boss; Cian Healy, Richardt Strauss, Mike Ross, Leo Cullen, Devin Toner, Sean O'Brien, Shane Jennings, Jamie Heaslip (capt).
Replacements: Jason Harris-Wright, Heinke van der Merwe, Simon Shawe, Nathan Hines, Dominic Ryan, Eoin Reddan, Gordon D'Arcy, Andrew Conway.