Young backs Luke Marshall, Paddy Jackson and Nevin Spence, who were all nursing ankle injuries, have returned to training this week and are available for selection. Mike McComish is also back fit after shaking off a shoulder injury.
Meanwhile, prop Declan Fitzpatrick's neck injury was reviewed last week and he is likely to be out of action for four to six weeks. Paddy McAllister and Peter Nelson also miss out.
Ulster's opponents on Friday, Leicester Tigers, have been hit by injuries to England internationals Toby Flood, Manu Tuilagi and Louis Deacon who are all ruled out.
Flood's replacement at out-half, Billy Twelvetrees, scored all of his side's points in their 29-11 Aviva Premiership win over London Wasps last Saturday.
Leicester have a formidable record in the Heineken Cup and have qualified for the knock-out stages ten times. They have contested five finals, winning back-to-back titles in 2001 and 2002, but losing the showpiece matches in 1997, 2007 and 2009.
Ulster are currently top of Pool 4 on 14 points, with the Tigers trailing by two going into this crunch match.
Defeat for either side would almost certainly end their dreams of reaching the last eight this season.
Clermont Auvergne are just one point behind Leicester in the pool standings and will travel to Aironi this weekend before hosting Ulster the following week.
ULSTER Squad (v Leicester Tigers) - Backs (14): Paul Marshall, Ruan Pienaar, Ian Porter, Ian Humphreys, Paddy Jackson, Paddy Wallace, Ian Whitten, Darren Cave, Nevin Spence, Stefan Terblanche, Craig Gilroy, Simon Danielli, Andrew Trimble, Adam D'Arcy.
Forwards (19): Callum Black, Tom Court, Adam Macklin, John Afoa, Jerry Cronin, Andi Kyriacou, Nigel Brady, Rory Best, Lewis Stevenson, Johann Muller (capt), Dan Tuohy, Tim Barker, Neil McComb, Stephen Ferris, Pedrie Wannenburg, Willie Faloon, Mike McComish, Chris Henry, Robbie Diack.