Ian Humphreys is set to make his 100th Ulster appearance after being named in the team for Friday's sold-out PRO12 clash with the Scarlets.
In one of three changes to the starting team, Ireland international Dan Tuohy has returned from injury to take his place in the second-row, while new signing, Mike Stanley, could make his debut after being named as a replacement.
The sole change in the backline sees Luke Marshall replace the suspended Stuart McCloskey at inside centre. Marshall is joined by Darren Cave in midfield, while Humphreys and Pienaar will orchestrate things from half-back. Elsewhere, Louis Ludik, Craig Gilroy and Michael Allen make up the back three.
Callum Black, Rob Herring and Wiehahn Herbst are retained in an unchanged front row and Franco van der Merwe will partner Tuohy in the engine room.
Roger Wilson will again captain the side from blindside flanker, with Nick Williams continuing at the base of the scrum and Clive Ross taking over from Mike McComish in the number seven jersey. Tim Boys picked up a toe injury in training and is unavailable for selection.
Ballymena duo John Andrew and Andrew Warwick provide front row cover along with Bronson Ross, Lewis Stevenson and McComish listed as the other forward replacements. Paul Marshall, Stanley and Rory Scholes, who returns to the first-team squad having recovered from injury, complete the matchday 23.
Meanwhile, Scarlets will take on Ulster at Kingspan Stadium with only one change to the team that came away with a draw against Munster at Parc y Scarlets last weekend.
South African lock George Earle comes in to the second-row for fellow South African Johan Snyman who is unavailable due to concussion after taking a knock in the opening ten minutes of the Guinness PRO12 clash against Munster last Saturday.
Last week's man of the match Hadleigh Parkes will make his tenth appearance for the Scarlets as he partners with fellow Kiwi Regan King in the centre.
Llanelli RFC's loosehead prop Rhys Thomas comes in on the bench, as front-row cover, with Rob Evans unavailable due to international duty. Thomas' first, and only appearance for the Scarlets so far, came in the LV= Cup clash against Sale Sharks earlier this month.
Welsh-qualified Australian lock-forward Jack Payne will be hoping to make his Guinness PRO12 debut from the replacements bench, having made two appearances in the LV= Cup against London Irish and Sale Sharks. Winger Kristian Phillips is the third change to last weekend's replacements bench.
Form: Ulster have won their last three matches in all tournaments and have lost just once at the Kingspan Stadium in the Guinness PRO12 since the start of the 2013/14 season: 20-22 to Leinster in round 21 last year. Scarlets have won just two of their last seven Guinness PRO12 fixtures, both at home, to Ospreys and Connacht, whilst the Welshmen have not won away from home in any tournament since the 8th February 2014 on a trip to Treviso in the PRO12. The two sides have already met on three occasions this season with each team winning its respective home game in the European Champions Cup, and sharing a 32-all draw at Parc y Scarlets on the opening weekend of the PRO12 campaign. Scarlets have not been victorious in Belfast since September 2008.
Ulster: 15 Louis Ludik, 14 Craig Gilroy, 13 Darren Cave, 12 Luke Marshall, 11 Michael Allen, 10 Ian Humphreys, 9 Ruan Pienaar, 8 Nick Williams, 7 Clive Ross, 6 Roger Wilson (c), 5 Franco Van der Merwe, 4 Dan Tuohy, 3 Wiahahn Herbst, 2 Rob Herring, 1 Callum Black.
Replacements: 16 John Andrew, 17 Andrew Warwick, 18 Bronson Ross, 19 Lewis Stevenson, 20 Mike McComish, 21 Paul Marshall, 22 Mike Stanley, 23 Rory Scholes.
Scarlets: 15 Jordan Williams, 14 Harry Robinson, 13 Regan King, 12 Hadleigh Parkes, 11 Michael Tagicakibau, 10 Steven Shingler, 9 Aled Davies, 8 John Barclay, 7 James Davies, 6 Aaron Shingler, 5 Lewis Rawlins, 4 George Earle, 3 Peter Edwards, 2 Ken Owens (c), 1 Phil John.
Replacements: 16 Ryan Elias, 17 Rhys Thomas, 18 Jacobie Adriaanse, 19 Jack Payne, 20 Rob McCusker, 21 Gareth Davies, 22 Adam Warren, 23 Kristian Phillips.
Date: Friday, February 27
Kick-off: 19:35 GMT
Venue: Kingspan Stadium
Referee: Ben Whitehouse (Wales)
Assistant referees: Barry Kieran (Ireland), Dermot Blake (Ireland)
Television match official: Marshall Kilgore (Ireland)
Assessor: Bertie Smith (Ireland)