Scrum half Martin Roberts starts with the exciting centre partnership of Jonathan Davies and Regan King reunited for the first time in a year. King starts in his second game for the region after returning from a long-term hamstring injury.
And Scarlets Head Coach Nigel Davies has given impressive young Llanelli full-back Dan Newton his first opportunity to start for the region. Dan Newton, 20, has been showing success with the boot in recent games in the Premiership with Llanelli RFC. Daniel Evans moves from full-back to the wing.
David Lyons captains the side for the away fixture against the Irish giants on Saturday evening with Magners League points vital to the Scarlets in their bid to climb the table and secure their place in Europe next season.
Head Coach Nigel Davies said: "Leinster are a strong squad and have depth, even without a number of their internationals and that's what you need to be successful as a team. It will be a big challenge for us but we'll look forward to a good game out there, we've been going pretty well in the past month.
"If you look at our season so far considering where we have come from, we can been reasonably happy with what we achieved, as runners-up in our group in the Heineken Cup and joint top of the LV=Cup pool. We need to concentrate on results in the Magners League now, we've come close a number of times in our Magners games, shown by the number of losing bonus points we've secured. We now have to turn those performances into results."
On selection, Davies said the Scarlets travelling away support could look forward to the centre partnership between Jon Davies and Regan King back on the field: "That's something to be excited about, it should be quite intriguing to see.
"In the backs, Dan Evans is comfortable on the wing, he has all the skills and pace needed and will slot in there nicely. Dan Newton has been playing well in the Premiership and deserves a chance. He came on in Connacht earlier in the season and made an impact and got us a bonus point in that game.
"He hasn't had many opportunities but we think he will link in well and do a good job for us.
"It's a big game for Ken Owens as well, he's being playing very well all year and if he maintains his consistency and puts in another strong performance at the weekend, he will be pushing hard for selection for Wales against France next week, no doubt."
The Scarlets squad is without wingers Morgan Stoddart who has a groin injury and will be out for six weeks as well as Lee Williams who has a fractured eye socket and will be out for four weeks. Other Scarlets on the long-term injury list include senior internationals Simon Easterby, Dafydd Jones (expected to return in March) and captain Mark Jones.
Scarlets selection v Leinster; Magners League 20th February 2010 (KO 1830) at Royal Dublin Society
15 Dan Newton, 14 Daniel Evans, 13 Regan King, 12 Jon Davies 11 Andy Fenby, 10 Rhys Priestland, 9 Martin Roberts, 1 Iestyn Thomas, 2 Ken Owens, 3 Deacon Manu, 4 Dominic Day, 5 Damian Welch, 6 Rob McCusker, 7 Johnathan Edwards 8 David Lyons (capt)
Replacements: 16 Phil John, 17 Emyr Phillips, 18 Rhys Thomas, 19 Vernon Cooper, 20 Josh Turnbull , 21 Tavis Knoyle, 22 Gareth Maule