Ben Youngs, England's first-choice scrum-half at the World Cup, is facing more time out after aggravating the injury that saw him miss a chunk of last season and reduced his preparation for New Zealand.

Youngs missed Leicester's Friday night Anglo-Welsh Cup victory over Gloucester and his director of rugby, Richard Cockerill, said it is too early to say when the 22-year-old is expected back. With Saracens' Richard Wigglesworth due for a scan on a damaged knee, two of the three scrum-halves selected for New Zealand will miss the resumption of the Premiership this weekend.

It is particularly galling for Cockerill, who wants his strongest team available to travel to Sale on Friday. Leicester are second from bottom of the table while Sale are in third position.

Youngs was injured at an England training camp in June and the left knee subsequently required surgery to trim cartilage. "We need to get the full low-down on what happened while he has been with England," said Cockerill. "But at the moment his knee is not good enough to play at this level.

"He's a world-class player and left us four months ago fully fit and has come back with a pretty average knee, so we need to get on top of that. We end up taking the hit player-wise but that always seems to be the way."

Wigglesworth limped off after 20 minutes against Exeter. Saracens have already lost Matt Stevens, the England prop suffering a sore back after being named on the replacements' bench for his first game back.