England back-row Tom Curry will play no part at all in this season's Six Nations after being ruled out for at least four weeks with a torn hamstring, it was announced on Wednesday.
Curry had only just returned from an injury to the hamstring on his right leg sustained while playing for club side Sale against Harlequins on 8 January.
The 24-year-old flanker had hoped to make his England comeback against Wales on Saturday, only to damage the same muscle on his left leg in training.
"It's a grade 2c hamstring injury on the opposite side to the one that he did six weeks ago," Sale boss Alex Sanderson said. "It's four to six weeks."
Curry's place in the England squad has been taken by his twin brother Ben, unexpectedly chosen ahead of Ben Earl despite the reigning Premiership player of the season's impact off the bench against Scotland and Italy in the opening two rounds of the Six Nations.
Saturday's match, however, could be scuppered by a threatened strike by Wales players, involved in a contract dispute with the Welsh Rugby Union.