England should have a more definitive idea over the availability of Manu Tuilagi for their autumn campaign on Wednesday afternoon after the Leicester centre sustained a suspected torn pectoral muscle.
Tuilagi is a major doubt for the November internationals against Australia, Argentina and New Zealand after Tigers director of rugby Richard Cockerill offered a best case scenario for his return of six to eight weeks.
The 22-year-old went for scans yesterday and the results are expected today, with Cockerill fearing it could even be longer term.
"Until we know exactly what the damage is it is hard to tell how long he will be out, but you'd think it is certainly weeks - potentially leading to months - rather than days," he said.
"Hopefully he has just partially torn a pec muscle - we're having it assessed. But it could mean surgery, depending on how severe it is."
Tuilagi sustained the damage towards the end of Leicester's 31-6 Aviva Premiership victory over Newcastle on Saturday in his first appearance for the Tigers since returning from the British and Irish Lions tour.
England's most effective ball-carrier, Tuilagi has been an ever-present since making his Test debut in 2011 and is the player feared most by the Wallabies, Pumas and All Blacks.
His absence, combined with the loss of foot injury-victim Brad Barritt, will force head coach Stuart Lancaster to field an inexperienced midfield combination this autumn.
Billy Twelvetrees and Kyle Eastmond are the remaining fit centres in Lancaster's elite player squad, although both play at 12 and Bath's Eastmond has been struggling with a knee problem incurred on the opening day of the season.
Anthony Allen, Luther Burrell, Elliot Daly, Jonathan Joseph and Joel Tomkins are in the England Saxons squad and will be hoping the injuries offer them the chance to impress Lancaster.
Burrell has been highly impressive for Northampton this season, although his game time has come at 12, while Henry Trinder's strong form for Gloucester could propel him into the reckoning despite his absence from either senior squad.
England have also lost flanker Tom Croft to knee surgery, almost certainly for the entire season.