Munster prop BJ Botha has been ruled out of action for up to a month after suffering a calf tear.
The South African, who has joined from Ulster, picked up the injury in Friday's friendly clash with Wasps at Musgrave Park and will now miss the Irish province's opening RaboDirect PRO12 fixtures, including their opener against the Newport Gwent Dragons.
A statement read: "Munster (on Monday) confirmed that prop BJ Botha will be sidelined for up to a month following a calf injury he sustained in Friday's clash with London Wasps at Musgrave Park."
James Coughlan was another forced off against Wasps, but his eye injury was not serious and he has returned to training.
Another man back in training is scrum-half Tomas O'Leary, who was a surprise omission from Ireland's World Cup squad.