The home side will play with true Scarlets passion and endeavour determined to secure a victory to strengthen their RaboDirect PRO12 league standings; their last win coming over Connacht at the Sportsground on 23rd November.
Head Coach Simon Easterby has made 11 changes, two of which positional, to the starting line-up that were cruelly stripped of victory over Munster at Musgrave Park last weekend.
Ospreys have not lost to a fellow Welsh Region in the PRO12 since they visited Dragons and were defeated 20-21 on 6th January 2012 whilst the Scarlets will look for a repeat of the 22-14 victory over the Ospreys at Parc y Scarlets two years ago.
Liam Williams and Kristian Phillips make positional changes with Williams moving to fullback 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.
Head Coach Simon 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."
Scarlets v Ospreys, Thursday 26th December, kick-off 2pm at Parc y Scarlets:
15 Liam Williams, 14 Kristian Phillips, 13 Nick Reynolds, 12 Scott Williams, 11 Frazier Climo, 10 Rhys Priestland, 9 Gareth Davies, 1 Phil John, 2 Ken Owens, 3 Samson Lee, 4 Jake Ball, 5 George Earle, 6 Aaron Shingler, 7 John Barclay, 8 Rob McCusker (c)
Replacements: Emyr Phillips, Rob Evans, Rhodri Jones, Richard Kelly, John Snyman, Rhodri Williams, Aled Thomas, Gareth Maule
Players not available due to injury: Deacon Manu (fractured arm), Jonathan Davies (pectoral), Chris Knight (shoulder), Steven Shingler (shoulder), Sione Timani (knee), Josh Lewis (hamstring), Jacobie Adriaanse (hamstring), Josh Turnbull (concussion), Adam Warren (concussion).
Guinness PRO12
Suite 208, Alexandra House,
The Sweepstakes
Ballsbridge, Dublin 4, Ireland