Leicester Tigers captain Ed Slater has been ruled out for up to two months with a knee injury, putting his participation in the Six Nations in doubt.
Slater is yet to make his Test debut for England but had been considered by many to be a contender for a place in new head coach Eddie Jones's squad, with some even suggesting that he could captain the side.
However, he will now miss at least the first half of England's campaign after damaging his medial ligament during his side's Aviva Premiership defeat to Saracens on Saturday.
"Ed has medial ligament damage. It's not too bad but it will probably be six to eight weeks. It's not ideal or what we needed," Leicester director of rugby Richard Cockerill is quoted as saying by PA.
"Hopefully he won't need surgery but we'll only be able to make a decision on that once the swelling has gone down.
"Thankfully the injury is not to the same knee that caused his problems last season. It's just bad luck rather than because of ongoing problems."
England begin their Six Nations campaign against Scotland at Murrayfield on February 6.
