Thomas called up for Corbisiero
England prop Alex Corbisiero is expected to miss the entire RBS 6 Nations with a knee injury, according to London Irish boss Brian Smith.
Corbisiero underwent a procedure on Wednesday to clear out a "loose body" on a knee which has been troubling him since the start of England's summer tour of South Africa.
The initial prognosis from England coach Stuart Lancaster was that Corbisiero would be sidelined for "the first two games (of the Six Nations) as a minimum".
But Smith told TalkSport tonight that Corbisiero will be out for up to 10 weeks - and there are doubts over whether he will even play again this season.
"Unfortunately for Corbs he had further surgery. The information our medical team have been given is that it is likely to be a 10-week injury," Smith said.
"I'd like to think he could get back on the park for us before the end of the season. There are still major question marks about that.
"He has a significant injury and he needs to be managed well."
England have called Sale prop Henry Thomas into the squad as "temporary injury cover" for Corbisiero.
Thomas will train with England ahead of Saturday's Six Nations opener against Scotland at Twickenham.
Harlequins' winger Ugo Monye has also been drafted into the 33-man training squad as Freddie Burns remains at Gloucester for treatment, also with a knee problem.
Meanwhile, the RFU also said Shaun Knight has withdrawn from the England Saxons squad as he, too, must return to Gloucester due to a knee injury.
The Saxons convene in Newcastle on Monday morning ahead of their match with Scotland A at Kingston Park on Friday.