Peter Horne moves from inside centre to fly-half, with Ruaridh Jackson dropping to the bench.
Alex Dunbar comes in for Horne, with Stuart Hogg, Sean Maitland, Niko Matawalu, Josh Strauss, Al Kellock and Ryan Grant also back in the starting XV.
Gregor Townsend said: "Leinster have set the benchmark in European rugby for the last three or four seasons and we are under no illusions as to the size of the challenge that awaits us in Dublin.
"Winning in Galway has created vital momentum for us after our home victory against the Ospreys. It was also important that we were able to deliver a quality performance away from home against tough opponents. We return to Ireland this weekend with renewed confidence and determination.
"We narrowly lost to Leinster in March but we were pleased with a number of aspects of our game that night. We've improved since then and we're really looking forward to another opportunity to play at the RDS."
Hogg replaces Peter Murchie at full-back, Sean Maitland comes in for Tommy Seymour on the right wing, with the clubs all-time leading try scorer DTH van der Merwe keeping his place on the left flank.
Dunbar will partner Sean Lamont at centre, with Horne starting at fly-half.
After signing a new deal this week to keep him at Scotstoun until 2015, Niko Matawalu starts ahead of Henry Pyrgos at scrum-half.
John Welsh keeps his place at tight head, with Ryan Grant coming in at loose head in place of Moray Low and Pat MacArthur continuing at hooker.
Captain Al Kellock is back in the side after missing the game against Connacht and he will partner Tim Swinson in the second-row.
Josh Strauss comes in for Rob Harley at blind-side, with Barclay starting at open-side and Ryan Wilson at number eight.
After signing a one-year deal this week, hooker Fraser Brown starts on the bench for the Warriors, with Dougie Hall out injured. Glasgow also have Ed Kalman, Moray Low, Tom Ryder, Rob Harley, Henry Pyrgos, Ruaridh Jackson and Mark Bennett in reserve.
This is the Warriors second successive appearance in the play-offs and it's a repeat of last year's fixture at this stage when they were narrowly beaten 19-15 by Leinster at the RDS.
The Warriors have the highest try count of any team this season in the RaboDirect PRO12, with 66. It is the third highest amount of tries scored in a single season since the Celtic League was formed in 2001. Cardiff Blues hold the record with 73 in season 2003/04.
Townsend said: "Training has been positive this week following our win in Galway and once again I've been delighted with the workrate and attitude from our players.
"We are disappointed for Dougie Hall who injured his knee against Connacht, but we're hoping he won't be out of action for too long. After signing on for next season Fraser Brown gets the chance to be involved again from the bench and he'll relish the opportunity.
"Everyone wants to play in semi-finals and finals and our group have worked extremely hard all season to get themselves into this position. A number of players are unlucky to miss out on selection, but I know that those who have been picked will give it everything tomorrow night."
Glasgow Warriors team to play Leinster in RaboDirect PRO12 Play-Off, RDS, Saturday 11 May (kick-off 7.35pm):
15 Stuart Hogg
14 Sean Maitland
13 Sean Lamont
12 Alex Dunbar
11 DTH Van der Merwe
10 Peter Horne
9 Niko Matawalu
1 Ryan Grant
2 Pat MacArthur
3 Jon Welsh
4 Tim Swinson
5 Al Kellock
6 Josh Strauss
7 John Barclay
8 Ryan Wilson
16 Fraser Brown
17 Moray Low
18 Ed Kalman
19 Tom Ryder
20 Rob Harley
21 Henry Pyrgos
22 Ruaridh Jackson
23 Mark Bennett
Not available for selection through injury:
M Cusack (shoulder), C Cusiter (shoulder), C Fusaro (groin), F Gillies (neck), D Weir (ankle), D Hall (knee)
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