Gloucester captain Luke Narraway could be ruled out of England's Six Nations opener against Scotland next Saturday after picking up a calf injury in training.
The flanker joined up with the England squad earlier this week following an injury to Tom Wood, but could miss his chance to establish a first-team spot if his injury doesn't heal in time.
The leading candidate to replace Narraway could be Leicester Tigers' Thomas Waldrom, who scored a try in England Saxons' 23-17 win over Ireland Wolfhounds on Saturday.
Interim coach Stuart Lancaster will name his first England starting XV on Thursday, ahead of Saturday's curtain-raiser at Murrayfield.