The UL Bohemians centre won his first cap by playing in the 22-20 defeat against the Pumas last Saturday in Santa Fe and is now preparing to start the second Test between the sides in Buenos Aires.
The World Cup is in the mind of every player in Eddie O'Sullivan's squad since the coach said 50% of his World Cup squad had yet to be confirmed.
Murphy is not an exception - and as a result tonight's game is more than just a Test for him.
He explained: "It is a happy camp out here and preparation for the two Tests has gone well.
"To tell you the truth, last weekend's result was not what we wanted but I think we played some great rugby.
"That game could have gone either way at the end. Hopefully we can do it this weekend, because I think we need a win to top off the tour."
Murphy believes Argentina are very good rivals to be tested, especially in their homeland.
He added: "It is a difficult place to play.
"Argentina have some brilliant players and this weekend they will have even more, as they have added a few players to the squad.
"It's going to be a difficult game.
"We don't have excuses for the defeat. They surprised us and it cannot happen again."
The Leinster hooker added: "It is our last chance to make a good impression for the team and for ourselves."