Wales face Argentina in Marseille on Saturday, while England face Fiji a day later at the Stade Vélodrome. Ireland play New Zealand in Paris on Saturday, before France meet South Africa the following day in the capital.
The four highest-ranked teams in the world will all play each other in Paris, leaving the matches in Marseille to the lowest-rated teams.
Wales boss Gatland has dismissed suggestions of an easy ride through half of the World Cup draw – saying a superior performance at the 2019 World Cup would have reduced the problem for the other teams.
“I just tell the other teams that they should have done better in the last World Cup, right?” Gatland said.
“That’s where the draw comes from. It’s not our fault that this happened. If teams had better performances and better results at the last World Cup, they would probably be in different groups.
“You didn’t hear us complaining in 2015 when we had Fiji, Australia and England in the same pool, we never complained about that. We give you the hand and you just have to take care of it.
Wales were able to recall the fit-again Dan Biggar to start at fly-half against the Pumas, while Jac Morgan will captain the side and move to blindside in the absence of Taulupe Faleutau.
Faletau misses after breaking his arm, with Aaron Wainwright at No.8 and Tommy Reffell at open flank.
Argentina coach Michael Cheika has named Wales as favorites for Saturday’s clash. Wales head coach Gatland was baffled by the call, but also unfazed.
Asked if he was comfortable with Wales being considered favourites, Gatland replied: “Yes, absolutely. I don’t know where Michael gets that from, he’s probably trying to relieve himself a little.
“We haven’t talked about the underdogs or the favorites, we just follow our own processes and work as hard as possible to make sure the preparation is good for Saturday.”
The Wales team will face Argentina in Marseille
Beginning of the 15th century:L Williams; L Rees-Zammit, G North, N Tompkins, J Adams; D Biggar, G Davies; G Thomas, R Elias, T Francis; W Rowlands, a beard; J Morgan (captain), T Reffell, A Wainwright.
Substitutes: D Lake, C Domachowski, D Lewis, D Jenkins, C Tshiunza, T Williams, S Costelow, R Dyer.