Replacements Dan Lydiate and Sam Lewis are the only changes to the Ospreys team that lost to Racing Metro last week.
Scarlets avenged their loss to Ulster with a 22-13 win to end the Irish side's hopes of European Rugby Champions Cup progress.
Scarlets coach Wayne Pivac thinks his side are firmly in the mix for qualification from their Champions Cup pool.
Ulster will bid to keep their slender Champions Cup hopes alive when they face Pool Three rivals Scarlets on Sunday.
Ireland international Darren Cave has re-signed with Ulster on a new three-year contract.
Ulster got their European campaign back on track with a 24-9 win over the Scarlets at the Kingspan Stadium on Saturday.
Coach Neil Doak was delighted with Ulster's efforts as they kept their European Rugby Champions Cup campaign alive.
Ulster will aim to keep their European Rugby Champions Cup hopes alive when they host Scarlets at Ravenhill on Saturday.
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