Cardiff Blues fly-half Rhys Patchell is facing an anxious wait after injuring his knee in Wednesday's win over the Dragons at the Arms Park.
Patchell was forced to leave the field after just half-an-hour when he landed awkwardly on the plastic turf in a bid to retrieve his own chip kick.
He will have the injury scanned when the swelling goes down but it is feared he will miss the Blues' potential Heineken Cup group decider with Toulon in Nice on January 11.
The injury could also scupper his chances of being included in the Wales squad for the upcoming Six Nations.
"We will assess Rhys and see how he is," Blues director of rugby Phil Davies told Walesonline.
Toulon are two points ahead of Cardiff at the top of Pool Two of the Heineken. If the Blues do the double over the tournament's defending champions and also beat Exeter Chiefs at the Arms Park on January 18 it would almost certainly secure their spot in the quarter-finals.
"We have got to see if we can get Patch patched up," added Davies.
"But, if not, Gareth Davies will be there and we have got confidence in him.
"He has done a fantastic job for us this season. He came on here against Toulon and won us the game.
"We know we have got a big job ahead of us, but Gareth has got the ability to play, with his handling skills and playing flat to the line.
"It's about getting him to show what he can do and lead the team around the pitch."
Patchell has battled injuries - He was also included in Wales' squad for the November Tests but sustained a shoulder injury in training and never played a game - during this campaign and hasn't made the same impact as when he arrived on the scene last season.
But Davies believes the young pivot, who has represented Wales in two Tests, will still do well.
"He's a guy who is only 20," he said.
"He's still young and raw but he's got an unbelievable attitude for a young fella.
"Rhys has got a huge mental toughness. It's a case of realising when to kick, pass or run, of seeing those things.
"It's all part of the learning process, but I'm so excited he's here for the next couple of years."