McCall has kept the faith with players that turned their game around in the second half against Leinster at Ravenhill with only two changes to the side. Kieran Campbell returns to the squad at the expense of Paul Marshall and hooker Nigel Brady drop from the side with Stuart Philpott being included in the squad for the first time this season.
McCall will name his starting team on Thursday by noon.
Ulster Squad
Backs: Mark Bartholomeusz; Isaac Boss; Tommy Bowe; Bryn Cunningham; Rob Dewey; David Humphreys; Kieran Campbell; Mark McCrea; Andrew Trimble; Paddy Wallace
Forwards: Neil Best; Rory Best (Captain); Stuart Philpott; Ryan Caldwell; Kieron Dawson; Carlo del Fava; Stephen Ferris; Declan Fitzpatrick; Justin Fitzpatrick; Justin Harrison; Roger Wilson; Bryan Young