Chris Henry and Craig Gilroy are also likely to return to action this Friday - both players were rested in the defeat in Scotland, following their exertions so far this season.
Ulster are also boosted by the return of All Black prop John Afoa, who returned to New Zealand temporarily after the Heineken Cup win over French giants Clermont Auvergne.
That means injured back-line stars Ruan Pienaar, Paddy Wallace and Jared Payne are the only players unavailable to the Ulster management.
The province will find comfort in returning to Ravenhill this week, where they have lost only once in their last 12 encounters.
The Scarlets are one of the form teams in Europe at present, and are undefeated in their last eight matches in all competitions since their 20-10 loss in Treviso last month.
There are still tickets available for Friday's game. They can be bought online at www.ulsterrugby.com or by calling the ticket office on 02890493222 (ticketing option). Alternatively, you can pay at the gate on match night.
Please be aware that ticket zoning and scanning will be in operation at the ground this season. Supporters should check their tickets to ensure that they are entering through the correct gate. More details are available here.
Ulster Rugby are advising supporters coming to the game (gates open at 5.30pm) to avoid parking in the immediate vicinity of the Ravenhill grounds. The following roads are only accessible for residents and closed to everyone else:
1. Onslow Parade
2. Ravenhill Park
3. Ravenhill Park Gardens
There will also be parking restrictions in place in the Castlereagh area (Mount Merrion Avenue). Supporters are encouraged to make use of the Park 'n' Ride facilities at Pirrie Park and along Montgomery Road.
ULSTER Squad (v Scarlets) - Backs (12): Paul Marshall, Ian Porter, Ian Humphreys, Paddy Jackson, Nevin Spence, Luke Marshall, Ian Whitten, Darren Cave, Craig Gilroy, Simon Danielli, Andrew Trimble, Adam D'Arcy.
Forwards (21): Paddy McAllister, Callum Black, Tom Court, Adam Macklin, John Afoa, Declan Fitzpatrick, Jerry Cronin, Andi Kyriacou, Nigel Brady, Rory Best, Lewis Stevenson, Johann Muller (capt), Dan Tuohy, Tim Barker, Neil McComb, Stephen Ferris, Mike McComish, Pedrie Wannenburg, Willie Faloon, Chris Henry, Robbie Diack.