Gatland does make one alteration to his replacements, though, with Lions Test star Gethin Jenkins finally back in the fold.
The Cardiff Blues prop, who won Lions honours in both 2005 and 2009, hasn't played since January because of toe and calf problems.
Jenkins takes over from Ryan Bevington as back up to Paul James and Adam Jones but there is no pace for fellow Lions Stephen and Ryan Jones.
Stephen had been declared fit to face the inform Samoans having missed the loss to the Springboks and all three World Cup warm ups with a calf injury but Gatland has not included him in his matchday 22.
The New Zealander, for whom this weekend's game will feel like a home match as it is being played in his native Hamilton, has kept faith with Scarlets youngster Rhys Priestland in the No10 shirt.
James Hook provides outside-half cover from full back, with Scott Williams and 2009 Lion Leigh Halfpenny beating Jones to a place on the bench.
Namesake Ryan hasn't recovered from a calf injury of his own so wasn't considered for selection but Gatland otherwise had a full squad to choose from as Wales look to build on their fine performance against the Boks.
"We were extremely disappointed to lose last week against the Springboks, but we did maintain momentum with aspects of the performance providing a host of positive points to take into Sunday's match against Samoa," said Gatland.
"We have regrouped and the players are looking forward to getting back out on the pitch to largely pick up where they left off last weekend.
"There are one or two areas we know we need to work on but we are looking for much of the same from all involved.
"We could not fault the effort, passion and commitment of the players last week and we have simply said we are looking for the same again against Samoa on Sunday."
Wales have been beaten in both previous World Cup encounters with the Samoans, with the islanders causing huge upsets in 1991 and 1999.
Victory over Australia earlier this summer gave the Welsh another reminder of how dangerous Sunday's opponents will be, while defeat once again would leave Wales facing an early World Cup exit.
But with plenty of positives from the 17-16 reverse to South Africa, Gatland hasn't shied away from talking about building for the knockout stages, especially as he believes Wales will get better the more time they spend in New Zealand.
"The stats in terms of territory and possession put us in a position that we were able to win the game, unfortunately we lost by a point," added Gatland.
"But we've got to pick ourselves up from that and start thinking about Samoa and the latter stages of this tournament.
"We've got to build from last week. We started well in terms of good performance [although] not a good result for us.
"One of the things that we have been able to demonstrate in the past is that we have been able to get better as a team as games and tours have gone on.
"We've got to make sure we get better this week in Hamilton on Sunday - kick your drop-goal and kick your penalty.
"That's how close the games are these days. That's how tight things are."
Wales (vs Samoa, Sunday, 4.30am BST)
James Hook;George North, Jonathan Davies, Jamie Roberts, Shane Williams, Rhys Priestland, Mike Phillips; Paul James, Huw Bennett, Adam Jones, Luke Charteris, Alun Wyn Jones, Dan Lydiate, Sam Warburton (captain), Toby Faletau
Replacements: Lloyd Burns, Gethin Jenkins, Bradley Davies, Andy Powell, Tavis Knoyle, Scott Williams, Leigh Halfpenny
NB Bold denotes Lion