England head coach Brian Ashton has added Sale scrum-half Richard Wigglesworth to his World Cup training squad as cover for Pete Richards.
Scrum-half Wigglesworth is also a talented kicker
London Irish player Richards is having treatment for a back problem which forced him to withdraw from England's bench for the 62-5 win over Wales.
Wigglesworth, 24, was England Saxons' first-choice number nine in this year's Churchill Cup.
A product of Sale's Academy, he can also play on the wing or at fly-half.
Richards' condition will become clearer as the week progresses, and it will be a setback to his World Cup chances if he is ruled out of contention for Saturday's warm-up match against France at Twickenham.
The game will be Ashton's last chance to assess his options before he announces his 30-man squad for the tournament on 14 August.
Scrum-half Shaun Perry cemented his place in that squad with a try-scoring, man of the match display in the win over Wales.
But Andy Gomarsall, who replaced Richards on the bench, could get a chance against France.
England are also waiting to discover the extent of the groin injury suffered by full-back Mark Cueto in the warm-up at Twickenham that forced him to withdraw before kick-off.
Captain Phil Vickery also came off at half-time with a knee problem, but insisted it was "fine" afterwards.