Gloucester full-back Olly Morgan will undergo further assessment on his injured shoulder this week.
He will see a specialist in London to determine the extent of the damage after being replaced during the second half of Gloucester's 31-7 Heineken Cup victory over Bourgoin last Friday.
"Of all the injuries we sustained on Friday, Olly's was the most serious but we are not in a position to fully determine the extent of the damage at the moment," said head coach Dean Ryan. "He will see a specialist and then we will have a much clearer idea of the nature of the injury and any likely recovery time.
"We are obviously disappointed for Olly because he was playing very well and any period of time on sidelines would be a set-back for him and the club."
There was more encouraging news regarding Iain Balshaw and Mike Tindall. Balshaw suffered a cut to the knee and Tindall limped out of the second half with a blow to the shin but both are expected to return to training later this week.
Chris Paterson, who also left the field midway through the second half, damaged ribs and after assessment today will continue to be monitored although the injury is not as serious as first feared.
"The prognosis of the other injured players is encouraging and the reason why we have a squad of such strength. We have tried to make it clear we needed to extend the pool of players we have in the first team environment and that process has been exceptionally valuable now," Ryan added.