Eoin Reddan is doubtful for the Heineken Cup clash against London Irish at Twickenham this Saturday, and there are concerns the Leinster scrum-half might not be available for the opening games of the Six Nations.
It is thought Reddan acquired an injury in the last few days, although Leinster last night declined to comment, a spokesman merely saying that there would be "no update until the team announcement" due tomorrow. Leinster only need a point to progress to the quarter-finals.
Meanwhile, Exile winger Salosi Tagicakibau may be included in coach Toby Booth's line-up. The return of their leading try-scorer this season would be a significant boost to a side who know they may almost certainly require a try-scoring bonus point to advance to the knockout stages.
Tagicakibau has not played since fracturing an ankle in London Irish's 9-9 draw at Harlequins in October.
"He has done two weeks' training now so I hope that potentially he is able to figure in some capacity," said Booth.
"You want your best players playing and he is there or thereabouts in relation to playing."
Exiles captain Bob Casey was given some time off from training this week, but he is expected back for the crunch clash this weekend.
"We let ourselves down badly at Parc y Scarlets," said Casey, in reference to how his side somehow conspired to convert a likely bonus point win into nothing.
"We came with a gameplan but didn't implement it. Everything we spoke about beforehand, it just seems like so much hot air.
"We conspired to fall off tackles all day. Saturday's game against Leinster now becomes a cup final."
Leinster's fullback Rob Kearney believes that the dramatic change in Pool 6 after Sunday's result means the Exiles now have to chase a win.
"If they want to qualify, they have to win. It's as simple as that," he said.