Will Chambers, who started on the bench against Castres, starts on this occasion, with the player he replaced that day, Danny Barnes named among the replacements. Otherwise the other changes are positional, Johne Murphy donning Howlett's number 14 jersey rather than the 15 he wore in Toulouse and Denis Hurley staying at full back where he has impressed in the most recent games against Edinburgh and Ospreys.
Speaking of yet another milestone in a remarkable career, O'Gara admitted the 100th cap was something that hadn't crossed his mind. "No, to be honest, it didn't. It wasn't something I was aware of until I was told.
"It was my privilege and honour to present John Hayes with his 100th cap after the game against Northampton Saints and I think it was entirely fitting that man should be the one to achieve that goal first.
"Right now the game tomorrow is far more important than any stat or personal record." he continued. "But when I'm finished playing, I've no doubt I'll recognise the significance because this is a fantastic competition and one that has given me every possible emotion."
Munster: D Hurley; J Murphy, W Chambers, L Mafi, S Zebo; R O'Gara, C Murray; W du Preez, D Varley, BJ Botha; D Ryan, P O'Connell capt; P O'Mahony, N Ronan, J Coughlan; Replacements: D Fogarty, M Horan, J Hayes, D O'Callaghan, D Leamy, T O'Leary, I Keatley, D Barnes.