Welsh Premiership player of the season Jacob Botica will look to impress Scarlets when he plays against last season's Pro12 champions at Llandovery on Saturday (16:00 BST).
Wayne Pivac's side face a Scarlets Premiership select side that includes RGC 1404's outside-half Botica.
He is the son of former Scarlets and New Zealand fly-half Frano.
New Scarlets signings Rhys Jones, Tom Grabham, Morgan Williams and Australian Paul Asquith all start.
None of the Scarlets' Wales or British and Irish Lions players have been included. The region's opposition will be a side, made up of promising future regional stars talent from Carmarthen Quins, Llandovery and Llanelli.
Scarlets: M Williams; T Grabham, I Nicholas, P Asquith, R Conbeer; R Jones, J Evans; D Evans, T Davies, N Thomas, D Bulbring, T Price, J Macleod, S Evans, J Condy.
Reps: D Hughes, R Fawcett, S Gardiner, J Helps, W Boyde, L Rawlins, D Smith, J Maynard, H Parkes.
Scarlets Premiership Select team: K Evans; A Warren, M Jenkins, R Jones, M Griffiths; J Botica, A Hemmings, R Thomas T Myhill, J Sebastian, J Jones, B Morgan, S Jones, S Worrall, J Powell.
Reps: M Moore, J Hughes, S Thomas, C Long, L Pike, L Reynolds, G George, R Davies, S Marshall, A Evans, J Evans.