Liam Williams, Jake Ball and George North are all injury concerns for Wales after a bruising weekend of European rugby.
Williams suffered an ankle injury playing for the Scarlets in their Champions Cup defeat at Saracens – and left the stadium wearing a protective boot – whilst Ball injured his ribs in the same match.
North injured his hand, with fears he may have broken a bone during Northampton’s defeat to Castres.
All three players could have expected to play a part for Wales against Australia on November 5, the opening match of the four-Test autumn series.
Scarlets coach Wayne Pivac said: “Hopefully Liam will be all right. He feels good in himself. He’s in a moon boot to give him the best opportunity to recover and get into that Wales camp next week.
“Jake is a bit sore at the moment. He has a rib injury and we’ll get that checked out. Hopefully the injuries won’t be too serious and we’ll know more over the next couple of days.”
Wales centre Scott Williams withdrew from the Scarlets team in the build up to the match.
“Scott has an ankle injury as well. There’s a bit of swelling there and he just didn’t quite recover in time. Another couple of days and he would have made it. He’ll be fine to go into camp next week,” added Pivac.
The Scarlets lost 44-26 at Sarries and were unable to back up their opening tournament victory over Sale with so much as a bonus point against the European champions.
But skipper and hooker Ken Owens was proud of their efforts and believes they are still very much in the hunt for qualification for the knockout stages with December matches against Toulon to come.
Owens said: “They don’t make errors and they play a very good territorial game. They put us under pressure, we cracked and put ourselves under pressure a lot of the time. There were some positives out there but we were second best really.
“Against the best team in Europe I thought we found some space and looked pretty sharp, attacking-wise.
“We’ve got to learn from this and front up the next couple of weeks. We saw massive character from the boys to keep going. We put them under pressure, we didn’t fold at any point during the 80 minutes.
“We kept playing, kept trying and everybody worked hard for the 80 minutes. We just came up against a better side.”
The Scarlets now sit third in pool three, level on four points with former champions Toulon.
Owens added: “We’ve got to dust ourselves off now. We had a good performance against Sale last week, we were disappointed here tonight. Sale and Saracens have showed the way in how to beat and play very well against Toulon. I thought Sale could have got a result against them.
“We’ve got to take heart, we’ve got a big challenge in those two back-to-back weeks in December. It’ll be another huge challenge against a formidable side, if we play a high tempo game and move their big pack around I’m sure we’ll get some gains.
“We have to be positive. We’ve already done better than last year. We have to keep building and keep plugging away. We exposed some of our youngsters tonight and giving them game time will only help our cause going forward.”