Six of the replacements for last Saturday's Amlin Challenge Cup quarter-final victory over Brive start this time around, the exception being John Hayes who again provides back-up for the front row.
Denis Hurley was expected to make a return to action but tweaked a hamstring in training on Thursday and that means a start for youngster Danny Barnes on one wing with another young gun, Simon Zebo, on the other.
Commenting on the changes, Munster head coach Tony McGahan said: "After three challenging weeks previous to this away trip to Scarlets, a rotation of the playing group allows us to rest many of the starters coming into a busy and competitive period.
"It also allows for competition within the squad for opportunities across the 23 and there is no better place or opposition for players to test themselves than the Scarlets at their home ground."
MUNSTER (v Scarlets): Paul Warwick; Simon Zebo, Johne Murphy, Lifeimi Mafi, Danny Barnes; Declan Cusack, Peter Stringer; Marcus Horan, Mike Sherry, Stephen Archer, Donnacha Ryan, Mick O'Driscoll, Tommy O'Donnell, Niall Ronan, Denis Leamy (capt).
Replacements: Denis Fogarty, Darragh Hurley, John Hayes, Alan Quinlan, Paddy Butler, Duncan Williams, Sam Tuitupou, Scott Deasy.