O'Leary was stretchered off just after he had set up Munster's opening try and was removed to the Cork University Hospital.
A statement issued by Munster Rugby confirmed that Tomas O'Leary sustained a fractured ankle last night in the course of the Magners League game against The Scarlets at Musgrave Park. O'Leary will have the injury assessed by a specialist on Saturday.
Commenting on the injury Munster coach Tony McGahan said, " It goes without saying that we are very disappointed to lose a player of Tomas's stature at this crucial stage of the season, even more particularly so, from his own personal point of view, given that he had just been selected to tour with the Lions, and our thoughts are with him in that regard.
"However in immediate terms, in Tomas and Peter Stringer we are fortunate to have two of the best scrumhalves in the country in our squad and the experience of Mike Prendergast to call on when required."
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