Ulster simply must deliver for tonight's sold-out clash with Munster at Ravenhill (kick-off 7.05 and live on BBC2) with a win now an essential requirement if they are to keep their PRO12 League campaign from going off the rails.

In a side which has been wholly changed from the one that was bravely beaten by Leinster on Boxing Day, due to the match scheduling that demanded Ulster play twice in four days, returning skipper Johann Muller has called for a big performance from his team-mates.

"It is a must-win game," Muller said. "We know what's coming, we know Munster, but we're at Ravenhill. We have a great record there and we want to keep it that way.

"There is so much pressure on us (particularly) now because we got rested this week and we're (coming into this) nice and fresh.

"We as a squad can learn from them (Munster) and get our performances up there every single week, not every second or third week, so they are probably the benchmark we need to get to."

A winning performance, against a much-changed Munster side which is also playing for the second time this week, will ensure Ulster are still in with a decent chance of reaching the League's play-offs as the eighth-placed Ravenhill squad are currently nine points adrift of the top four zone.

Ruan Pienaar, Ian Humphreys, Darren Cave, Chris Henry and Craig Gilroy are all back in an Ulster shirt again while temporary replacement Stefan Terblanche gets his first start on the right wing.

Ulster are without their Ireland contingent of Stephen Ferris, Rory Best, Andrew Trimble and Tom Court while Simon Danielli and Tim Barker are ruled out due to sickness.