Munster produced a stunning first-half performance as they defeated struggling Dragons 38-19 in their United Rugby Championship clash.
Mark McCall’s Saracens were amongst the losers, but they at least could hold heads high in Limerick after an exhausting bonus-earning 12-17 loss at Munster.
Munster picked up a signature Champions Cup win as they downed Saracens 17 - 12 in an old school tussle at Thomond Park.
There is no return for O’Mahony, whose last appearance came in the December 13 defeat at Castres.
Ahead of the highly anticipated URC matchup between Leinster and Munster, both teams have welcomed back multiple players to their starting lineup.
Munster Rugby secured a 33 – 7 victory over Stade Francais at Thomond Park to get their Investec Champions Cup campaign off to the perfect start.
The Irish province, who got rid of head coach Graham Rowntree last month after just two wins in six league matches this season, are down a number of front row options due to injury.
The Sharks are set to welcome back World Cup winning South Africa centre Lukhanyo Am for their contest against Connacht at Kings Park tomorrow in the United Rugby Championship.
The Sharks and the Ospreys meet in a historic match at the Twickenham Stoop on Friday night, as it will be the first time a United Rugby Championship match has ever taken place in England.