Gloucester are sweating on an injury to Danny Cipriani after he was hurt during a 29-17 Heineken Champions Cup defeat against Exeter Chiefs.
The England international fly-half went off just before the interval at Kingsholm after taking a heavy knock to his arm and pectoral area.
Gloucester head coach Johan Ackermann said: "He is in a sling and the big thing now is what the investigation will find.
"They originally thought it was in his shoulder, but it looks like it is more in the pectoral (chest) area.
"I don't want to guess. They have to do the full investigation to see the extent of the injury, but hopefully it is something that won't keep him off for weeks and months."
Exeter turned the tables on Gloucester and breathed life into their Champions Cup campaign with a bonus point success.
Gloucester would have gone top of Pool Two had they repeated last Saturday's win against the Chiefs in Devon, but it proved a frustrating night for them.
Exeter's forwards dominated the contest, with lock Sam Skinner, flanker Don Armand, hooker Jack Yeandle and prop Harry Williams scoring tries.
Cipriani's opposite number Gareth Steenson kicked three conversions and a penalty as Gloucester managed two Jason Woodward touchdowns and a Tom Hudson try, plus a Billy Twelvetrees conversion.
The result leaves Munster in pole position for a quarter-final place if they beat French champions Castres on Saturday.
Gloucester and Exeter are not out of the running, but Munster - they visit Kingsholm next month and have Exeter at home - remain strong group favourites.
"It is going to be quite challenging for us now," Ackermann added. "It was a bit of a blow.
"We took a lot of confidence out of last week, but we were not there tonight.
"We let this one slip. On the night, we were not good enough. Credit to Exeter, their set-piece was good and their defence was good.
"Our discipline was poor. Last week, we only gave away four penalties in the match. Tonight, it was something like 15 or 16.
"We were that half a yard slow in everything that we did. Last week, we were quite physical, whereas tonight we only played in patches."
It was Exeter's first European win of the season, and said everything about their squad depth as a number of frontline players were absent.
Reflecting on the victory, Exeter rugby director Rob Baxter said: "It means there is a real value in the Castres home game next month. There is a glimmer.
"At the end of the day, if we can end up going to Munster with something to play for in our last game, it would be a fantastic thing for us to look forward to if we can get there.
"We put a bit of pressure on ourselves this season to do better in the Champions Cup, and sometimes if you put a bit of pressure on yourselves, the one thing you can forget to do is to enjoy yourself.
"We will stop, draw breath and enjoy tonight."
PA
