It's never easy deciding who to select
England lock Geoff Parling has been ruled out of Saturday's opening November international against Australia at Twickenham with concussion.
Parling was concussed during a training session at England's training base in Bagshot, south-west of London, on Tuesday and will now follow the standard procedure for players who've suffered head injuries.
"Geoff Parling sustained a mild concussion during a contact session this afternoon and will undergo the recommended graduated return to play protocol," said England coach Stuart Lancaster in a Football Union statement.
"As such, he will be unavailable for Saturday's game but will stay in camp with a view to returning to training next week."
Eleven players were sent back to their Premiership clubs from the training camp - meaning they won't feature in the Test.
They are Freddie Burns (Gloucester), Luther Burrell (Northampton Saints), Danny Care (Harlequins), Kyle Eastmond (Bath), Alex Goode (Saracens), Tom Johnson (Exeter Chiefs), Matt Kvesic (Gloucester), Henry Thomas (Sale Sharks), Henry Trinder (Gloucester), Rob Webber (Bath) and Christian Wade (London Wasps).
"It's never easy deciding who to select and that's what you want - players pushing hard for places across the board," Lancaster said.
"We have had two good days of training here at Pennyhill Park and, added to last week in Leeds, we are in good form and looking forward to the game."
Alex Corbisiero (knee) will also return to camp for continued treatment.
Forwards: Dave Attwood (Bath), Dan Cole (Leicester Tigers), Dylan Hartley (Northampton Saints), Joe Launchbury (London Wasps), Courtney Lawes (Northampton Saints), Joe Marler (Harlequins), Ben Morgan (Gloucester), Chris Robshaw (Harlequins), Billy Vunipola (Saracens), Mako Vunipola (Saracens), David Wilson (Bath), Tom Wood (Northampton Saints), Tom Youngs (Leicester Tigers).
Backs: Chris Ashton (Saracens), Mike Brown (Harlequins), Lee Dickson (Northampton Saints), Owen Farrell (Saracens), Toby Flood (Leicester Tigers), Ben Foden (Northampton Saints), Joel Tomkins (Saracens), Billy Twelvetrees (Gloucester), Marland Yarde (London Irish), Ben Youngs (Leicester Tigers).