Johann Muller ruptured thumb ligaments during the Heineken Cup pool victory over Glasgow Warriors at Scotstoun Stadium last month, yet he has made a quicker than expected recovery and should play some part in Sunday's league fixture.
Rory Best has been sidelined with a neck injury he sustained against the Dragons a month ago. However, the experienced hooker has recovered well and could return to action earlier than expected.
Chris Henry and Ruan Pienaar have earned a week off after playing in all three November Internationals for Ireland and South Africa respectively, but both will return for the Heineken Cup round 3 game against Northampton Saints on Friday, December 7.
Ulster's superb unblemished start to the 2012/13 campaign continues apace with eleven straight wins in all competitions.
Mark Anscombe's charges are attempting to complete a clean sweep of victories away from home to the Welsh regions this season.
ULSTER Squad (v Scarlets) - Backs (11): Michael Heaney, Paul Marshall, Niall O'Connor, Paddy Jackson, Luke Marshall, Darren Cave, Tommy Bowe, Andrew Trimble, Craig Gilroy, Jared Payne, Peter Nelson.
Forwards (14): Rob Herring, Rory Best, Callum Black, Tom Court, Declan Fitzpatrick, John Afoa, Neil McComb, Johann Muller, Dan Tuohy, Iain Henderson, Robbie Diack, Mike McComish, Roger Wilson, Nick Williams.