England will be without Tom Croft for at least their first two RBS SIx Nations fixtures after the injured flanker was ruled out for five to six weeks.
The Leicester Tigers player suffered medial knee ligament damage in his club’s 47-8 Heineken Cup win over Viadana on Saturday.
He will therefore miss the clashes against Wales and Italy, and his participation against Ireland at Twickenham on February 27 is also in doubt.
A statement from the Rugby Football Union read: “A scan has confirmed that Tom Croft (Leicester Tigers) sustained a grade two medial cruciate ligament injury to his left knee in the Heineken Cup game against Viadana last weekend.
“He has now started his rehabilitation programme with a view to returning to action in five to six weeks.
“The England Team medical staff will continue to work closely with Leicester Tigers during his recovery process.”
Croft established himself firmly in the international line-up during last year’s Six Nations, where he was used as a substitute in the first three games and impressed sufficiently to earn a starting spot for the final two matches against France and Scotland.
He has since become a key figure in England’s plans and earned a place on the British & Irish Lions’ summer tour of South Africa as a late call-up after Munster’s Alan Quinlan was ruled out by suspension.
He made an immediate impact with a try in the first tour match against the Golden Lions and added two more in the first Test against the Springboks.
The Viadana game was just his second appearance since returning from that lay-off, but rugby director Richard Cockerill had no regrets about pitching him into the action.
He said after the match: “It’s a blow for the lad to injure the same knee, and while England manager Martin Johnson might be concerned about Tom’s Six Nations situation, my only concern is that we won’t have him in Swansea next weekend.
“I have my job to do, Martin has his. But Crofty is a world class player who hadn’t seen action for ages. He needed playing time, so I had no qualms starting him.”
Northampton’s Courtney Lawes will be one of the men in contention to replace Croft after being promoted to the senior squad ahead of the tournament. Harlequins back-rower Nick Easter is also back in the 32-man party after injury.