He has a shoulder injury
Peter O'Mahony looks set to miss Munster's Champions Cup opener against Bayonne next week with a shoulder injury.
O'Mahony has already been ruled out of their URC clash with Glasgow Warriors at Musgrave Park.
Head coach Graham Rowntree has confirmed that Simon Zebo is also unavailable for this Friday's game.
Meanwhile, La Rochelle head coach Ronan O'Gara will face a Top 14 disciplinary hearing just days before their Champions Cup opener against Leinster.
The former Munster out-half was reported by match officials for his behaviour during Saturday's 32-10 defeat to Racing 92.
The defending champions host Leinster at the Stade Marcel Deflandre next Sunday.