Stuart Lancaster fears Manu Tuilagi, the man who spearheaded the autumn destruction of New Zealand, could miss England's opening Six Nations game against Scotland.
Tuilagi scored one try and set up two others in England's record 38-21 triumph over the world champions, but he is struggling with an ankle injury.
"I need a decision to be made early, by the weekend preferably, because if Manu is not available then there will be decisions to be made," Lancaster said.
If Tuilagi cannot prove his fitness, Lancaster's most likely move would be to start with either Jonathan Joseph or Billy Twelvetrees alongside Brad Barritt.
Lancaster would also have the option of bringing Toby Flood back in at out-half and shifting Owen Farrell into the centre, where he started his England career 12 months ago.