Leigh Halfpenny will miss Scarlets' crunch European Champions Cup clash at Bath on Saturday (AEDT) after failing a fitness test.
The Wales full-back had hoped to return against the Pool 5 leader at The Rec, but a pectoral muscle injury will keep him on the sidelines.
Wing Johnny McNicholl was also ruled out after the captain's run at Parc y Scarlets on Thursday due to a shoulder problem.
Rhys Patchell will remain at full-back in the absence of Halfpenny, while Tom Prydie starts on the right wing with McNicholl still unavailable.
Scarlets can leapfrog Bath and Toulon with a win against the Premiership side in the penultimate round of the pool stage.