England will be without hooker Dylan Hartley and second-row Courtney Lawes for their opening autumn international against Fiji.
The Northampton pair both suffered knee injuries in the Saints' defeat to Saracens and have returned to their club to undergo further treatment.
While Anthony Allen, Mike Brown, Phil Dowson, Ben Morgan, James Haskell, Jordan Turner-Hall and Ben Youngs have all been released for Premiership duty this weekend.
Worcester prop Matt Mullan and Harlequins lock George Robson, who were initially called up as injury cover for Joe Marler and Lawes, will train with England on Wednesday before returning to their clubs.
However, England head coach Stuart Lancaster insisted those players are still in contention for the Fiji game on 10 November.
"Some return for further treatment from their club and others to get some game time to put a marker down for selection for when we meet again on Sunday after the weekend's games," Lancaster said.
"We will not finalise selection for the Fiji game until after training next Tuesday and so for those going back and playing this is a real opportunity to stake a claim with a really big performance."
How many autumn internationals will England win?