England have suffered a double injury scare ahead of Saturday's RBS 6 Nations opener against Scotland at Twickenham.
Full-back Iain Balshaw and replacement flanker Lewis Moody have both picked up injuries but will be subjected to final checks by England's medical staff on Wednesday.
Gloucester star Balshaw has a groin problem, while Leicester forward Moody is suffering from shoulder trouble.
As a precaution, Balshaw's Gloucester team-mate Olly Morgan and Wasps flanker Tom Rees have been summoned to join the squad at their Bath University training base.
Morgan and Rees, who are both uncapped, are due to play for England Saxons against Italy A in Exeter on Friday night.
But they could now find themselves pressed into unexpected Six Nations duty instead as England prepare to launch the Brian Ashton era.
Ashton has already carried out major surgery on the team beaten by South Africa in his predecessor Andy Robinson's last match at the helm in November.
He made 11 changes and two positional switches from the side that played that day, when England slumped to an eighth defeat in their last nine Tests.
If Balshaw, whose England career has often been stalled by injuries, is forced out, then Aston at least has options.
He can put Morgan straight into the side or leave him on the bench, with Josh Lewsey or Jason Robinson probably moving to full-back and Mathew Tait starting on the wing.
Rees for Moody, though, would undoubtedly be a straight swap.