Leinster are sweating on the fitness of Brian O'Driscoll ahead of their Heineken Cup showdown with the Ospreys.
The three-time European winner was set to face Munster in a Pro12 derby this weekend.
But he has been ruled out of the clash due to a calf strain, which could also have implications on his involvement in the opening round of the Heineken Cup.
"Brian O'Driscoll picked up a minor calf strain in training this week and will be assessed by the medical team over the coming days regarding his availability for next week's opening Heineken Cup clash away to the Ospreys," read a Leinster statement.
New signing Lote Tuqiri makes his first appearance for the province and lines up alongside Gordon D'Arcy in the centre.
Sean O'Brien also starts for the first time since his heroics for the British & Irish Lions in Australia, while Jamie Heaslip captains the side.
"The squad are boosted by the return of several players including Australian Lote Tuqiri who starts at outside centre alongside Gordon D'Arcy in a new-look midfield," continued the statement.
"Jamie Heaslip will lead the squad for the 15th time for the trip to Limerick on what will be his 168th appearance for the province.
"The Naas man is named in a back-row which includes fellow Ireland international Kevin McLaughlin and the returning Sean O'Brien."
As part of the build-up to next month's Cardiff 2014 Heineken Cup and Amlin Challenge Cup finals weekend, ERC has joined forces with the WRU, Cardiff Blues and adidas to develop an annual grassroots community rugby programme targeting young players.
The Ulster Rugby full back, Jared Payne (No 15), has been suspended for two (2) weeks following an independent Disciplinary Hearing in Dublin arising from the Heineken Cup quarter-final match against Saracens at Ravenhill Stadium on Saturday, 5 April.