The Great Britain scrum-half suffered the injury in the friendly at Halifax last Wednesday and could be out for up to six weeks. "Reber was already on the bench and will now play a bigger part in the game," said the Wigan coach, John Monie.
"We want to see how he is when he gets off the plane, because Jason Robinson could be our better option."
Robinson started out as a scrum-half and has switched there occasionally during matches in recent seasons. If Monie opts for that tactic, Wes Davies, a highly promising outside-back who happens to be Billy Boston's grandson, will come in on the wing.
Reber has the advantage have having played regularly alongside Wigan's new stand-off, Greg Florimo, at North Sydney, so it is likely that he and Robinson will split the job between them.
Wigan have had more bad news, learning that their Great Britain Academy forward, Andrew Isherwood, who made his first-team debut last season, will be out for two months with a broken shin.
The former Wigan captain, Shaun Edwards, has been named as the new captain of the London Broncos, in preference to Peter Gill, who took over from Terry Matterson last season and was expected to retain the job.
The former Wigan hooker, Martin Hall, who also played for both Halifax and Castleford during a nomadic 1998, has signed for Hull and is likely to play against Cas in their Challenge Cup tie on Sunday.
Workington Town have given up on their Australian scrum-half, Josh White, after he failed to arrive to start the season. His contract has been cancelled.Reuse content