Tandy has replaced the injured Ryan Jones, who led the side last week, with Wales and British & Irish Lions lock Ian Evans. Elsewhere in the pack, James King partners Evans in the second row with Tom Smith leading the side from blindside flanker. Richard Hibbard and Adam Jones look set to provide a real impact as replacements.
Tito Tebaldi and Dan Biggar continue at halfback after the Italian's promising debut in his homeland. Richard Fussell, Ben John and Eli Walker provide the firepower out wide.
"It was good to get off to a positive start last weekend. We wanted to build some real momentum in the opening weeks of the season and although there's plenty of room for improvement, there's a lot to be happy about after a tough game in Italy," said Tandy.
"The spirit and effort shown by the boys was fantastic. It was backs to the wall stuff and we came through a very difficult test.
"Looking forward to this weekend, there's been plenty to work on off the back of last Saturday but the attitude of the group has been good.
"Leinster away is always tough and we wouldn't expect it to be any different this weekend. They've got strength in depth and whatever team they pick, we know we are going to have to be at our best to be able to build on the win in Treviso and keep the momentum going.
"We want to come back to the Liberty next week to play Edinburgh on the back of another positive performance."