The Wales international flanker will make his first appearance since January with Sam Costelow, Tom Rogers and Henry Thomas all coming into the side from last weekend’s 20-20 draw against Benetton in Treviso.
Up front, Kemsley Mathias continues at loose-head in an all-international Wales front row alongside Ryan Elias and Thomas, who will make his URC debut.
Alex Craig and Max Douglas combine again at lock.
In the back row, Vaea Fifita is ruled out with the knee injury he picked up against the Italian’s which forces a reshuffle.
Jarrod Taylor moves to blindside, Plumtree switches to number eight and Macleod starts in his favoured number seven shirt.
Johnny Williams and Macs Page continue in midfield, while Gareth Davies will make his 250th appearance from scrum-half.
The Wales and British & Irish Lions half-back made his Scarlets debut in 2009 in a career that has spanned 17 seasons.
There is a reshuffle in the back division. With Costelow recovering from the illness that forced him to miss the Benetton clash, the Wales fly-half returning to the number 10 jersey.
Ioan Lloyd switches to full-back and Rogers moves to the right wing in place of Ellis Mee, who is named among the replacements.
New signing Alec Hepburn has overcome the hamstring injury he picked up in the early weeks of pre-season and comes onto the bench, while there is also a return for Dan Davis and Eddie James.
Scarlets XV to face Cardiff:
Ioan Lloyd, Tom Rogers, Macs Page, Johnny Williams, Blair Murray; Sam Costelow, Gareth Davies
Kemsley Mathias, Ryan Elias, Henry Thomas , Alex Craig, Max Douglas, Jarrod Taylor, Josh Macleod (captain), Taine Plumtree.
Replacements:
Marnus van der Merwe, Alec Hepburn, Sam Wainwright, Jac Price, Dan Davis, Efan Jones, Eddie James, Ellis Mee.
[Lead image: Scarlets Rugby]
