Jimmy Gopperth will make his senior debut at half-back alongside Eoin Reddan, who is fresh from his successful return last weekend against Northampton Saints to make his 80th Leinster appearance.
Gordon D'Arcy returns to the starting line-up after missing the PRO12 and Amlin Challenge Cup final victories last May and the Wexford man will combine in the centre with Fergus McFadden.
The fit-again Luke Fitzgerald, who will make his first appearance since March, forms an exciting back-three with David Kearney and the back-line's second debutant, St. Mary's College captain Darragh Fanning.
Up front, Shane Jennings leads the team and is one of four Ireland internationals in the pack.
There are two Leinster Academy prop graduates Jack McGrath and Martin Moore named in the front row, while Mike Ross and summer signing Mike McCarthy are listed on the bench.
LEINSTER (v Scarlets): David Kearney; Darragh Fanning, Fergus McFadden, Gordon D'Arcy, Luke Fitzgerald; Jimmy Gopperth, Eoin Reddan; Jack McGrath, Sean Cronin, Martin Moore, Tom Denton, Devin Toner, Rhys Ruddock, Shane Jennings (capt), Jordi Murphy.
Replacements: Aaron Dundon, Jack O'Connell, Mike Ross, Mike McCarthy, Dominic Ryan, Isaac Boss, Noel Reid, Brendan Macken.