Aaron Shingler returns to the back row alongside Josh Turnbull and new skipper Rob McCusker at No8, with new South African signing George Earle and former Osprey Richard Kelly in the second row.
Scarlets Head Coach Simon Easterby said: "We know that Leinster are without a number of their internationals and key players but we will never underestimate the quality that they bring at any time. They have real depth, with strong players throughout their squad and their ability to get results in both the league and Europe sets them apart as a team. They have a tough mental edge, lots of belief and we know that we're up for a big challenge on Saturday evening.
"However, we're pleased with our preparations and we want to get off to a strong start and set a standard for ourselves this season - particularly at our home ground with Parc y Scarlets becoming an increasingly difficult place to come and win.
"We want success the same as every other club in this league and with top five finishes in the last two season and just a few points off both times - we know we can get there. We were three points off a semi-final place in the RaboDirect PRO12 last season and knew we should have been there - and that frustration coupled with our ambition is a real driver for all of us now.
"Facing Leinster four times this season, both sides will be looking to get the upper hand early in the season so there's a lot riding on this game but the boys have been really focused this week and it's been a very positive week's training.
"We've worked the lads really hard this summer to get them in the best shape possible and to give them the best platform to go out and perform - and we know they'll take that forward with determination and spirit on Saturday night.
"While we were frustrated with elements of our game last week and we'll need to keep our shape with the ball, but there was plenty in our performance against London Welsh that showed our character and ability as a group. And the boys are just eager to get our season underway and put everything into this big opening game at our home."
Easterby says leading the Scarlets is one of the biggest responsibilities and most exciting challenges of his rugby career to date: "This rugby region and being a Scarlet has such a hold on you as a person and player. Coming into my first game as Head Coach of the Scarlets and on our home soil is just a very exciting time for me. If someone told me as a player 13 years ago, I'd be here and doing this job, I may have laughed.
"We want to be competing at the top now as we move from our development phase into a performance era. We need to be in the mix for winning things and have a firm belief in our ability to achieve that as a squad.
"It's been a busy couple of months in the new role, but I am really enjoying it, feel very comfortable and confident about what we can achieve and it's great to have so much support and backing from the coaches, players and the business - so we're all in a really good place."
Scarlets: 15 Liam Williams, 14 George North, 13 Gareth Maule, 12 Scott Williams, 11 Andy Fenby
10 Aled Thomas, 9 Tavis Knoyle, 1 Rhodri Jones, 2 Ken Owens, 3 Deacon Manu, 4 George Earle, 5 Richard Kelly, 6 Aaron Shingler, 7 Josh Turnbull, 8 Rob McCusker (capt)
Replacements: 16 Matthew Rees, 17 Phil John, 18 Samson Lee, 19 Sione Timani, 20 Kieran Murphy, 21 Gareth Davies, 22 Rhys Priestland, 23 Jonanthan Davies.