Second row Dan Tuohy injured a hamstring during Friday's game against the Newport Gwent Dragons, but has been named in the initial squad as he hopes to get the all clear from an MRI scan.
Internationals Paddy Wallace, Stephen Ferris, Andrew Trimble and BJ Botha all remain sidelined through injury.
McLaughlin has been boosted by Luke Marshall's return to training after a wrist injury and he may feature if required on Friday night.
Heineken Cup finalists Leinster are possibly the form side in Europe at present and they have not been defeated at the RDS this season.
Ulster captain Rory Best said: "We're going down to Dublin as Magners League semi-finalists but we're not going to settle for that, we go there full of confidence as we have only lost four times in 2011.
"We know it is going to be a tough game but if you're going to win this competition it's not going to be easy.
"We have worked hard over the last month after the disappointment of the Northampton game to get ourselves in a position where we came to Rodney Parade to get a win and put ourselves into the semi-final and that is exactly what we have done."
Leinster travelled to Ravenhill in December and won 30-13 and handed McLaughlin's men a 34-26 defeat at RDS last month.
ULSTER Squad (v Leinster) - Backs (15): Ruan Pienaar, Paul Marshall, Ian Humphreys, Paddy Jackson, Ian Whitten, Luke Marshall, Nevin Spence, Darren Cave, Mark McCrea, Simon Danielli, Tommy Seymour, Craig Gilroy, Conor Gaston, Jamie Smith, Adam D'Arcy.
Forwards (16): Jerry Cronin, Tom Court, Paddy McAllister, Declan Fitzpatrick, Rory Best, Nigel Brady, Andi Kyriacou, Dan Tuohy, Johann Muller, Neil McComb, Tim Barker, Pedrie Wannenburg, Thomas Anderson, Ali Birch, Chris Henry, Robbie Diack.