Ian Humphreys is named in the extended Ulster panel, despite his late withdrawal from the Scarlets match due to a shoulder injury.
Paddy Jackson, who made an impressive debut at out-half in Humphreys' absence, has been released to rejoin the Ireland Under-20 squad.
Darren Cave returns to the province's senior squad for the first time since November after recovering from a hamstring injury. Prop Alan Whitten earns a recall to the squad, but there is no place for full back David McIlwaine.
Friday's last-gasp win over the Scarlets was a huge boost to Ulster and they are now just five points adrift of the play-off zone, with a game-in-hand. A victory over play-off rivals Cardiff would be another step in the right direction.
ULSTER Squad (v Cardiff Blues) - Backs (13): Ruan Pienaar, Paul Marshall, Ian Humphreys, Niall O'Connor, Ian Whitten, Nevin Spence, Luke Marshall, Darren Cave, Simon Danielli, Tommy Seymour, Craig Gilroy, Jamie Smith, Adam D'Arcy.
Forwards (16): Jerry Cronin, Declan Fitzpatrick, Paddy McAllister, Bryan Young, Alan Whitten, Nigel Brady, Andi Kyriacou, Ryan Caldwell, Neil McComb, Johann Muller, Tim Barker, Pedrie Wannenburg, Thomas Anderson, Willie Faloon, Chris Henry, Robbie Diack.