Victor Costello has been forced out of the Ireland squad to travel to Krasnoyarsk, Siberia for Saturday's World Cup qualifying tie against Russia.
Costello injured his calf in the second half of Leinster's Celtic League defeat to Connacht on Friday night.
Costello's replacement will be named shortly.
He is the second back row player to withdraw from the Irish squad in the last seven days. Eric Miller pulled out of the trip last week with a rib injury.