Scarlets boss Simon Easterby has made 11 changes to his starting XV for their Boxing Day clash with the Ospreys at Parc y Scarlets.
Two of Easterby's changes are positional, to the run-on side that were cruelly stripped of victory over Munster at Musgrave Park last weekend.
Liam Williams and Kristian Phillips make positional changes with Williams moving to full-back in place of Gareth Owen and Phillips changing wings with Frazier Climo coming in to make up the back three.
An all-new centre partnership sees Wales international Scott Williams pair up with Nic Reynolds with Rhys Priestland and Gareth Davies returning at half backs.
Veteran prop Phil John returns to bolster the front row alongside Welsh internationals Ken Owens and Samson Lee. George Earle links up with Jake Ball at second row with Aaron Shingler returning from injury replacing injured Josh Turnbull.
Scottish international John Barclay and Rob McCusker retain their places in the back-row with McCusker leading the side for the big Boxing Day clash.
Easterby said: "These games are a massive part of our season, for players and coaches alike these big games, with the huge traditions that belong to them, are what we work towards and relish being a part of.
"You don't have to get players up for derbies and big traditional fixtures like these. The back-to-back nature to the derbies, with us heading back over the Loughor Bridge in little over a week's time, will add a bit of spice to things."
Meanwhile, Ospreys boss Steve Tandy has named a strong starting line-up for this derby.
They are on a high after last weekend's narrow victory over the Cardiff Blues and are currently in fourth spot on the table.
Tandy said: "It was a good win against Cardiff on Friday night, an important one that gives us some momentum going into the Domino's Derby Series games against the Scarlets.
"It's been pleasing over the last couple of weeks to see the number of young Welsh players pulling on the shirt, and they've done the region proud, showing that the Ospreys have a bright future.
"Equally important though has been the role played by some of the experienced players, leaders who bond the group together, and that is why it is so important that we are able to keep these players at the region to give us leadership on and off the field and strength in depth.
"There was a big crowd and a good atmosphere in Cardiff, Boxing Day is heading towards a sell-out with another big crowd at the Liberty next week, which is fantastic for regional rugby.
"It's an exciting time of traditional rivalries and history, games that supporters want to see week-in week-out, against familiar old opposition. The numbers coming to these games says it all.
"We're looking forward to these two games against the Scarlets. Going back-to-back against them is something new and it gives the games an extra bit of spice, as if that's needed in this derby. It's a great opportunity for fans to get out and support the cause, really showing what their region means to them."
Form: Ospreys have not lost to a fellow Welsh Region in the PRO12 since they visited Dragons and were defeated 20-21 on January 6 2012 and head into the match having won back-to-back matches over Castres in the European Cup and the Cardiff Blues in the PRO12. The Scarlets will look for a repeat of the 22-14 victory over the Ospreys at Parc y Scarlets two years ago. Scarlets have slipped to four straight defeats in all competitions since beating Connacht 24-21 in Galway in the PRO12 last month. They have also defeated Ospreys just once in their last ten meetings, since 2007.
Scarlets: 15 Liam Williams, 14 Kristian Phillips, 13 Nick Reynolds, 12 Scott Williams, 11 Frazier Climo, 10 Rhys Priestland, 9 Gareth Davies, 8 Rob McCusker (c) 7 John Barclay, 6 Aaron Shingler, 5 George Earle, 4 Jake Ball, 3 Samson Lee, 2 Ken Owens, 1 Phil John.
Replacements: 16 Emyr Phillips, 17Rob Evans, 18 Rhodri Jones, 19 Richard Kelly, 20 John Snyman, 21 Rhodri Williams, 22 Aled Thomas, 23 Gareth Maule.
Ospreys: 15 Sam Davies, 14 Hanno Dirksen, 13 Ashley Beck, 12 Ben John, 11 Jeff Hassler, 10 Dan Biggar, 9 Rhys Webb, 8 Ryan Jones, 7 Sam Lewis, 6 Joe Bearman, 5 James King, 4 Alun Wyn Jones (c), 3 Adam Jones, 2 Richard Hibbard, 1 Duncan Jones.
Replacements: 16 Scott Baldwin, 17 Marc Thomas, 18 Aaron Jarvis, 19 Ian Evans, 20 Morgan Allen, 21 Tyler Ardron, 22 Tito Tebaldi, 23 Tom Isaacs.
Date: Thursday, December 26
Kick-off: 14:00 GMT
Venue: Parc y Scarlets
Referee: Leighton Hodges (Wales)
Assistant Referees: Sean Bricknell (Wales), Wayne Davies (Wales)
Citing Commissioner: Russell Howell (Wales)
TMO:Tim Hayes (Wales)