O'Mahony takes over the captaincy from brother Barry, who led the side in the final two B&I Cup pool games, and starts at full-back.
Academy player Darren Sweetnam starts on the right wing with Luke O'Dea returning on the opposite flank for his first Munster A game since injuring his hand against Plymouth in December.
Cian Bohane, who has featured in all six of Munster A's B&I Cup games this season, and academy player Harry McNulty start together in the centres. McNulty makes his first Munster A appearance since starting against the Eagles in the first game of the season.
It's an all-academy half-back pairing as Johnny Holland maintains his place at out-half after recovering from bruised ribs with Brian Haugh at scrum-half.
Academy prop Niall Horan starts in the front-row with UL Bohemians' hooker Kevin O'Byrne and Alan Cotter, who made his full Munster debut against Connacht in the PRO12 in December.
Ian Nagle is the most experienced player in the squad and he joins academy lock Darren O'Shea in the second-row.
Shannon's Lee Nicholas of the sub-academy starts his first game for Munster A in the back-row along with academy players Ryan Murphy and Shane Buckley.
Murphy started his first B&I Cup game of the season away to Plymouth in December with Buckley having featured in all seven of Munster A's games this season.
There are three academy players on an extended nine-man replacements bench, out-half Rory Scannell, utility back David Johnston and winger Alex Wootton.
UCC hooker Ben Burns, Mike Lynch of the sub-academy, UL Bohemians and St.Senan's, and Conor Glynn of Shannon provide the front-row cover.
Cork Con back-row Luke Cahill is also named on the bench along with Shannon and sub-academy player Aidan Butler, brother of Paddy. UCD and sub-academy back Jamie Glynn is also included.
Munster A team to face Connacht Eagles on Friday at 2:30pm
Ronan O'Mahony (Capt.); Darren Sweetnam, Harry McNulty, Cian Bohane, Luke O'Dea; Johnny Holland, Brian Haugh; Niall Horan, Kevin O'Byrne, Alan Cotter; Ian Nagle, Darren O'Shea; Lee Nicholas, Ryan Murphy, Shane Buckley. Replacements: Ben Burns, Mike Lynch, Conor Glynn, Luke Cahill, Aidan Butler, Jamie Glynn, Rory Scannell, David Johnston, Alex Wootton