Ian Humphreys, who damaged his shoulder against Cardiff, has responded well to treatment and should be available for selection this week.
The chosen squad is along expected lines, although young half-backs Blane McIlroy and James McKinney have been included and are pushing for selection.
Both sides go into this weekend's game unbeaten and are locked on 12 league points, just one behind current leaders and reigning champions Munster.
The Ulstermen's only defeat in their last nine matches against Welsh opponents was in the equivalent game at the Liberty Stadium last season when they narrowly lost 23-22.
ULSTER Squad (v Ospreys) - Backs (13): Paul Marshall, Blane McIlroy, Ian Porter, Ian Humphreys, Paddy Jackson, James McKinney, Luke Marshall, Nevin Spence, Ian Whitten, Craig Gilroy, Conor Gaston, Jared Payne, Adam D'Arcy.
Forwards (16): Jerry Cronin, Paddy McAllister, Declan Fitzpatrick, Adam Macklin, Andi Kyriacou, John Burns, Nigel Brady, Tim Barker, Lewis Stevenson, Dan Tuohy, Neil McComb, Pedrie Wannenburg, Mike McComish, Chris Henry, Willie Faloon, Robbie Diack.