Gatland has made 14 changes from the starting XV which beat England in Cardiff a fortnight ago with the New Zealander announcing his final 31-man World Cup squad on Sunday.
Josh Navidi will captain the side for the first time while uncapped duo Owen Lane and Rhys Carre have been handed starts. Gatland insists places are still up for grabs and his backed his players to come out all guns blazing.
“There are a number of positions still up for grabs: front row, second row, back row, back three, the 10 position,” said Gatland.
“The players are still pretty well aware of how important this game is and the opportunity they get to put their hands up for selection on Sunday.
“Jarrod gets an opportunity, we know a little bit more about Rhys Patchell, so the pressure is on him [Evans] and he understands that fully. It’s about getting out, starting a game and controlling a game.
“Rhys will get the second half and it’s about him coming on and making an impression. The two of them are pretty aware that they’ll get the chance on Saturday and it’s probably a shootout between the two of them.
“Owen Lane has continued to improve and impress. Both Owen and Rhys Carré have fitted in well and hopefully they make the most of their opportunity.”
This will be Gatland’s final time coaching Wales at Principality Stadium with the 55-year-old departing at the conclusion of the World Cup. Despite admitting it will be emotional, Gatland insists Saturday is about the players and not himself.
“It’ll be quite emotional,” he said.
“I’ve had an unbelievable time here in Wales, the people have made my time incredibly special. I’m trying to keep it in perspective.
“It’s something I’ll be thinking about but it’s not about me. There are 31 players getting selected on Sunday and I have to make sure the performance and the job of picking the squad is incredibly important.
“There’s no way that I want to overshadow what is probably more important for those individuals than me having my last game in the stadium. I’ll just have a personal reflection and look back on how memorable it’s been without making a big fuss about it.”
