Wales prop Rob Evans will miss the remainder of the season because of a shoulder injury that requires surgery.
The 35-cap loose-head, who started four games in his country’s Grand Slam campaign, picked up the knock in the Scarlets’ 20-12 loss to Edinburgh.
The West Walians are looking to salvage an improbable Guinness PRO14 playoff place from a difficult season and they are chasing Heineken Champions Cup qualification, too.
Evans will be sidelined for the remaining regular-season games against Zebre this weekend the Dragons on Judgement Day, plus anything else that might follow in 2018-19.
Warren Gatland will doubtless be monitoring the situation, but the setback is not expected to affect Evans’ World Cup hopes.
Wyn Jones comes in for him against Zebre in Llanelli on Saturday (5.15pm), while Josh Macleod takes over from James Davies at openside flanker, with the latter laid low by an oblique injury.
In the backs, an illness sees Steff Evans miss out and Ioan Nicholas feature on the left wing.
The match is set to be the last at Parc y Scarlets for Will Boyde, who is poised to be released at the end of the season. The popular flanker is named at blindside and the certainty is supporters will want to give him a good send-off.
His region sit fifth in Conference B with head coach Wayne Pivac refusing to give up in the twin-quest for a top-three finish in the PRO14 and a shot at a Champions Cup qualifier in May.
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“Our focus is on 10 points from our last two games, it is as simple as that,” said head coach Pivac.
“This is our final home game of the season and we want to deliver an 80-minute performance we can all be proud of. We want to finish with a bang.”
The verdict on the Wayne Pivac era at the Scarlets as he prepares to say goodbye
The match will be an emotional one for Pivac, his final home fixture with the Scarlets.
While this season hasn't gone as expected, he is likely to be remembered fondly by many out west as the man who restored swagger and style to the region, with the Guinness PRO14 title success in 2017 the indisputable high water mark of his reign.
Scarlets : L. Halfpenny; J. McNicholl, J. Davies, H. Parkes, I. Nicholas; D. Jones, G. Davies; W. Jones, K. Owens (capt), S. Lee, L. Rawlins, S. Cummins, W. Boyde, J. Macleod, U. Cassiem.
Reps: M. Jones, P. Price, W. Kruger, J. Helps, E. Kennedy, K. Hardy, R. Patchell, K. Fonotia.
Zebre : E. Padovani; G. Di Giulio, G. Bisegni, N. De Battista, P. Balekana, M. Azzolini, G. Palazzani; D. Rimpelli, O. Fabiani, M. Ciccioli, S. Ortis, G. Biagi (capt), M. Mbanda, J. Brown, R. Giammorioli.
Reps: M. Cecilani, D. Fischetti, F. Alongi, L. Krumov, A. Tayavuca, J. Renton, M. Bellini, J. Elliott
