Murphy, 23, grew in influence with Leinster last season, making 18 appearances in the RaboDirect PRO12 and starting for the first time in Europe.
However, Sean O'Brien's return to the fold after injury - and the good form of Rhys Ruddock and Shane Jennings - meant there was no place for Murphy in Leinster's RaboDirect PRO12 final matchday squad.
That has not deterred Ireland head coach Joe Schmidt from naming him in the starting XV for the first Test in Argentina - and Murphy does not intend to waste his chance to impress.
"I'm just generally excited really," he said. The team and I have settled in well I think and we've had two hard days training now, we're getting all our moves together and kind of gelling together as well.
"We're just looking forward to a battle on Saturday. It's my first start for Ireland so I'm really excited about that and I'm just looking to repay the faith the coaches, Joe especially have shown in me to give me that first start.
"One of the dreams you'd have growing up (is to represent your country). Obviously it's happened for Leinster a few times now and I had two games off the bench for Ireland but I've been looking for that start and I'm going out to make the most of it and leave a mark."
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