PAT Sanderson will not be available for England's first three RBS 6 Nations games after suffering a new back injury playing for Worcester Warriors in their Guinness Premiership victory over Bristol.

The Warriors captain, who had only just returned from a back problem, will be out for four to six weeks and will miss the games against Wales (February 4), Italy (February 11) and Scotland (February 25).

Sanderson said: "I am obviously gutted. I felt things went well for me in the autumn and I had worked hard to get back for last week. But you have to accept these things happen in rugby and I am just looking forward to getting fit for Worcester and hopefully England."

England head coach Andy Robinson said: "I am disappointed for Pat, Worcester and England because he will be sorely missed. He was outstanding for us in the autumn and played very well in that first-half for Worcester against Bristol before coming off. I am looking forward to welcoming him back into the squad."

George Chuter (Leicester Tig-ers), man-of-the match against Sale Sharks on Saturday, is also out of contention for the first game because of a medial knee ligament strain.

Better news for Worcester was that another player making his comeback after injury, hooker Andre Van Niekerk, came through the Bristol game unscathed.

Sixways chief John Brain admitted that Van Niekerk's withdrawal in the first-half was always part of the plan.

"Andre is fit," said Brain. "He started the game. It was just a question of whether he played 25 minutes at the end or 25 minutes at the start."

Overall, Brain was delighted with the 26-23 win in front of a passionate crowd, especially after Bristol looked to be in control when they scored a try after charging down Shane Drahm's kick.