The Blues, who will be looking to build on a 22-17 victory over London Wasps in their opening fixture of the competition last week, have made two changes in the backs with Harry Robinson returning on the wing and Rob Lewis getting the nod at scrum-half.
Up front, Andries Pretorius comes in at No 8 to captain the team and is joined in the back row by Thomas Young who starts at openside flanker.
Scarlets head coach Simon Easterby has opted for a blend of youth and experience as he looks to try and bounce back from last weekend's 34-18 defeat at Worcester.
Gareth Maule and Gareth Owen will combine in the centres, while Dan Newton returns from injury to start at fly-half.
New Australian second-rower Jake Ball will make his second start for the club, while Wales U20 stars Kirby Myhill and Samson Lee come into the front row.
Kick-off is at 6.30pm.
Cardiff Blues: Dan Fish, Harry Robinson, Owen Williams, Gavin Evans, Tom James, Gareth Davies, Robert Lewis; Andries Pretorius, Thomas Young, Luke Hamilton, James Down, Macauley Cook, Ryan Harford, Marc Breeze, Sam Hobbs.
Replacements: Rhys Williams, Campese Mafu'u, Foa Filise, Cory Hill, Rory Watts-Jones, Lloyd Williams, Ceri Sweeney, Rhys Patchell.
Scarlets: Liam Williams, Kristian Phillips, Gareth Maule, Gareth Owen, Andy Fenby, Dan Newton, Rhodri Williams, Shaun Hopkins, Kirby Myhill, Samson Lee, Jake Ball, Johan Snyman, Craig Price, Johnathan Edwards (capt), Kieran Murphy.
Replacements: Emyr Phillips, Phil John, Jacobie Adriaanse, Joel Galley, Dan Thomas, Gareth Davies, Aled Thomas, Nick Reynolds.
Gilbert has released a new line of rugby cleats. The Gilbert Virtuo 8S is part of the exciting new product. Check it out.
The entire All Blacks apparel line has been updated for 2013/14. Check out the New Zealand All Blacks polo.
The Nike Tiempo is a solid rugby cleat and one of few styles still made from full-grain natural leather.
The Gilbert Blitz 8S rugby cleat is a great cleat at a great price of $69.99. Get a new pair of cleats today.
A cool looking all black rugby cleat with the high performance adidas is known for. Get in the Gear!
Wear the crest of the British and Irish Lions on your t-shirt. A great look for the summer.
The All Blacks Performance t-shirt is black with hints of blue from the training jersey. Very Cool.
The New Zealand All Blacks training jersey for 2013/14. Get in the Gear!
The USA Rugby Pro Alternate rugby jersey is perfect for any fan of the Eagles. Get yours to wear during the summer Test matches.
The NEW All Blacks 2013/14 jersey has arrived at World Rugby Shop. Dare to wear the colors of the All Blacks.