Ulster teammates Andrew Trimble and Luke Marshall have both been ruled out of Ireland's upcoming autumn internationals through injury.
Winger Trimble is expected to be out of action for "a period of months" after suffering ligament damage in his toe.
Meanwhile, centre Marshall is to spend around six weeks on the sidelines while he recovers from a knee problem.
Ireland play their first autumn international on November 8 when they welcome South Africa to Dublin.
