The selected side includes wingers Doug Howlett and Johne Murphy and flanker David Wallace, who all touched down in last weekend's 22-16 victory over the Ospreys in Limerick.
James Coughlan, who impressed in the back row last time out, has held onto the number 6 jersey ahead of the benched Alan Quinlan.
In a key incident in last Sunday's game, Coughlan managed to gather a loose ball close to his try-line, with Ospreys dangerman Tommy Bowe looming. Tony McGahan highlighted the importance of a moment like that.
"It's the same every season, you don't really know in particular games when those moments are, only when they're gone," explained Munster's head coach.
"I remember back in the 2007/08 season when we played Clermont Auvergne away and Rua Tipoki held up Elvis Vermeulen over the line in the 58th minute.
"They score then and we don't get the bonus point, we don't go through and we don't get to win the Heineken Cup.
"So moments like that stand out - that one particular effort or mistake can certainly derail the season.
"You don't know when they're going to come, you've got to approach every one as if it's a championship action. So we need to make sure we've got that hunger and desire on Saturday and I'm sure we will."
Giving his thoughts on the round 4 tie, lock Donncha O'Callaghan said: "There is the little bit of edge to this round (with the back-to-back scenario).
"There will be afters from last week and it really is only half-time. We've had our 80 minutes at home and now have to do it away as well.
"It was a relief to get the home leg of this out of the way because, essentially, you have to win at home. You don't have a hope of advancing otherwise.
"That's done now and it's time to refocus to see what we can get. We have to pick up a result (away) at some stage and this is it - like the last ten minutes last week it is really backs-to-the-wall stuff.
"We simply have to get a result (away) in the next few weeks. Better to start now, so we'll see how we go on Saturday."
Given the six-day turnaround, Munster confined themselves to just one on-field training session this week, at Cork IT on Wednesday.
They flew out this morning, arriving in Cardiff International Airport shortly after 1pm, and will take part in the Captain's Run at the Liberty Stadium later this afternoon.
MUNSTER (v Ospreys): Paul Warwick, Doug Howlett, Keith Earls, Sam Tuitupou, Johne Murphy; Ronan O'Gara, Tomas O'Leary, Wian du Preez, Damien Varley, Tony Buckley, Donncha O'Callaghan, Mick O'Driscoll, James Coughlan, David Wallace, Denis Leamy (capt).
Replacements: Mike Sherry, Darragh Hurley, John Hayes, Donnacha Ryan, Alan Quinlan, Peter Stringer, Lifeimi Mafi, Denis Hurley.