England lock Simon Shaw will miss the start of their Six Nations campaign after suffering an ankle injury in Wasps' Heineken Cup exit to Munster.
Shaw was forced off early in the second half against Munster
Shaw, 34, was stretchered off early in the second half after falling awkwardly beneath a pile of bodies.
He has sustained soft tissue damage which will keep him on the sidelines for several weeks.
That will rule him out of England's opener against Wales and probably their second match against Italy in Rome.
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."
And a Wasps statement added: "He will undergo review and treatment on his injury,
confirmed as soft tissue damage, throughout this week."
Shaw was almost certain to have started for England against Wales after playing a key role in their World Cup campaign last year.
The second rower started every game in France bar the group win over Tonga and England coach Brian Ashton will now have to decide who will replace him when the squad gather for Six Nations training on Monday.
Leicester second-row Louis Deacon and Bath's Steve Borthwick are the other locks in the squad while Ashton could turn to the Saxons and call up London Irish's Nick Kennedy or Tom Palmer of Wasps.
Meanwhile, Wasps director of rugby Ian McGeechan was unhappy with the performance of referee Nigel Owens in the game at Thomond Park and criticised his decision to give Shaw a yellow card late in the first half for not retreating 10 yards at a penalty.
The Scot said: "Simon's sin-binning was crucial but these are the things that you have to live with in big games.
"We were on the receiving end of some tough calls and in a marginal game it's the little things like that become huge.
"Some of those decisions in the first half, had they gone for us, might have swung the pendulum in our way."