Brad Shields is out for six weeks and is in a race against time to be fit for the World Cup. Photo: Matthew Childs/Reuters

England flanker Brad Shields will be sidelined for four to six weeks after damaging a ligament in his foot at a training camp in Italy last week, assistant coach John Mitchell said on Tuesday.

Shields, 28, was replaced by Harlequins' Alex Dombrandt at the training camp and the Wasps back-row forward's recovery period casts doubts over participation in England's warm-up matches before the World Cup in Japan in September.

Head coach Eddie Jones is set to name his final 31-man squad on Aug. 12  a day after a warm-up game against Wales at Twickenham  and Mitchell said the Australian coach would take the final call.

"Brad has got a tear in the lower foot," Mitchell told reporters. "It's always a little bit niggly, but it's four to six weeks for him. But we will continue to appraise his recovery and see where he gets to.

"Obviously we've got a deadline and that's important, but Eddie will decide on who's right and who's not right. There's plenty of time to go and there are no major concerns."

England play three more warm-up matches after the squad is announced  away to Wales and at home against Ireland and Italy  before heading to Japan, where they kick off their campaign against Pool C opponents Tonga on Sept. 22.