Both Stephen Jones and captain Matthew Rees left the field with injuries during their 35-27 Heineken Cup triumph over Benetton Treviso, the team that beat them on the opening weekend of league action.
The Scarlets have a busy festive period on the horizon with games against the Ospreys and Newport Gwent Dragons and both players could be doubts.
Stephen Jones appears to be the biggest worry. The talismanic fly-half hobbled off the field after just 17 minutes in their European tie with a knee ligament injury.
With the extent of the injury currently unknown, Jones could face an extended spell on the sidelines.
"It will take 24 to 48 hours to have an accurate assessment," said Scarlets coach Nigel Davies after the game.
"It's probably a tweak to the ligaments but we don't really know. He's walking around, so that's a good sign.
"In the next couple of days we'll have a clear assessment. We will have it scanned after the swelling has gone down."
Skipper Matthew Rees was also replaced in the bonus-point triumph and Davies later revealed the powerful hooker had been struggling with an abductor problem that raises question marks over his availability over the next few weeks.
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