Jake Ball and John Barclay have both been ruled out, with a knee and forearm injury respectively, which sees Tom Price and Jack Condy coming into the starting XV for the New Year clash.
Scrum half Gareth Davies, who pulled up in last Saturday's warm up with a calf injury, returns to the starting line up with Aled Davies named on the bench.
With injuries to James Davies, John Barclay, Rory Pitman and Will Boyde hooker Emyr Phillips is named as backrow cover on the replacements bench.
Speaking ahead of the second festive derby Pivac said: "This game becomes the most important game, I know it's a cliché and we say it every week, but when you're managing a squad like we are with injuries it puts pressure on the group.
"We know we're in for a battle up front against the Blues. The good thing about playing them at home is we know what the conditions will be like and it's going to be firm underfoot."
Despite missing out on the victory, and West Wales bragging rights, on Boxing Day Scarlets remain at the top of the Guinness PRO12 table, only a point ahead of Connacht in second place.
Pivac went on to say: "After our performance on the weekend, and not getting over the line, other results went our way and we remain where we are. Having said that there are eight teams who could all finish in the top four.
"It's a huge month. Blues and Connacht are our focus at the moment before we head back into European competition.
"The PRO12 has been such an enthralling competition this year I think."
Scarlets side to take on Cardiff Blues on Friday 1st January 2016, kick-off 5.00pm, at BT Sport Cardiff Arms Park;
15 Michael Collins, 14 Steff Evans, 13 Gareth Owen, 12 Hadleigh Parkes, 11 DTH van der Merwe, 10 Aled Thomas, 9 Gareth Davies, 1 Rob Evans, 2 Ken Owens ©, 3 Samson Lee, 4 Tom Price, 5 Lewis Rawlins, 6 Aaron Shingler, 7 Jack Condy, 8 Morgan Allen
Replacements: Kirby Myhill, Phil John, Rhodri Jones, Maselino Paulino, Emyr Phillips, Aled Davies, Steve Shingler, Regan King
Unavailable for selection: Will Boyde (foot), James Davies (foot), Peter Edwards (elbow), Rory Pitman (bicep), Liam Williams (foot), Scott Williams (knee), Tom Williams (shoulder), Tom Phillips (concussion), Michael Tagicakibau (hamstring), Jake Ball (knee), John Barclay (arm), George Earle (calf)
Guinness PRO12 Scarlets News
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