England second row Simon Shaw could miss the entire RBS 6 Nations after sustaining an ankle injury in Wasps' 19-3 European Cup defeat by Munster.
Shaw was carried off on a stretcher in the 49th minute after falling awkwardly beneath a pile of bodies and sustained soft tissue damage.
The incident capped a miserable night for holders Wasps who were dumped out of the Cup with a resounding loss at Thomond Park with Munster progressing to the quarter-finals.
A Wasps spokesperson said: “There was no break to the ankle but Simon sustained soft tissue damage.
“He is still in discomfort and will be out for several weeks.”