Davies will wear the No 12 jersey as the lone change to the starting line-up that took the field last weekend for the European Challenge Cup win over the Cheetahs in Italy.
That means Johnny McNicholl, Steff Evans and Ryan Conbeer will continue in the back three, and Ioan Nicholas will get a third successive run-out at outside centre in tandem with Davies after impressing during the European block.
Autumn Nations Series Wales squad half-backs Sam Costelow and Dane Blacker will once again combine, while up front the same back will start from last weekend. Sam Lousi will make his 50th appearance for the region in the second row.
There is plenty of experience in the all international back row, where Aaron Shingler, Sione Kalamafoni and Josh Macleod link up. There is one change on the bench with Scott Williams named among the backline cover.
“After wins for both sides last weekend, this game is nicely set up and both sides need to win as well. Both of us have been in games and come out on the wrong side of results when they have been tough battles,” said Scarlets head coach, Dwayne Peel.
“We had a good tussle at the start of the season which ended in a draw and I’m sure it will be a big battle again. This is not just another game, it is a big derby and I want the boys to treat it that way.
“This is always a big occasion and the emotion is part of it. I remember playing at the Liberty with a capacity crowd on a Boxing Day and you remember those games as players and as supporters.”
Scarlets: Johnny McNicholl; Steff Evans, Ioan Nicholas, Jonathan Davies (captain), Ryan Conbeer; Sam Costelow, Dane Blacker; Kemsley Mathias, Ryan Elias, WillGriff John, Vaea Fifita, Sam Lousi, Aaron Shingler, Josh Macleod, Sione Kalamafoni
Replacements: Ken Owens, Steff Thomas, Javan Sebastian, Tom Price, Tomás Lezana, Kieran Hardy, Rhys Patchell, Scott Williams.
Unavailable because of injury
Tom Rogers, Harri O’Connor, Wyn Jones, Johnny Williams, Jac Price, Callum Williams, Samson Lee.