Kumamoto - Wales coach Warren Gatland is billing Sunday's Rugby World Cup match against minnows Uruguay as a trial for quarter-final spots after he named a vastly rearranged side following the battering it took to overpower Fiji.
Australia's 27-8 bonus-point win over Georgia on Friday means Wales need only a draw against the South Americans to secure top spot in Pool D and a quarter-final against France.
In the unlikely event that Uruguay cause an upset in Kumamoto, far higher on the Richter scale than their shock win over Fiji, then Wales will finish second and play England in the quarter-finals leaving Australia to play France.
After the bruising Wales took in beating an enthusiastic Fiji 29-17 on Wednesday, Gatland has made 13 changes and put his entire 31-man squad on notice that his preferred run-on side for the play-offs is not yet settled.
"The message to the players against Uruguay is that the door is not shut," the New Zealand-born coach said.
"There are opportunities for players to go out there and impress and stake a claim for a quarter-final spot."
Injured flyhalf Dan Biggar (head), centre Jonathan Davies (knee) and wing George North (ankle) were not considered but wing Josh Adams, who limped off with a leg knock after scoring three tries against Fiji, will start again as will midfield linkman Hadleigh Parkes.
Justin Tipuric starts in the back row and will captain the side with Alun Wyn Jones rested after leading the side through the first three games.
"Ideally, we'd have given Josh a rest but that hasn't been the case. That's why we've gone with a six-two split on the bench with the two nines covering. We can cover a number of positions. We can move guys around," Gatland said.
Rodrigo Silva, who started on the bench for Uruguay in their historic 30-27 victory over Fiji and is again among the replacements against Wales, said the win over the Pacific islanders was inspirational but it was the way they played against Australia, despite the 45-10 scoreline, that gave them hope.
"We played a great first half and we went toe to toe with a team who are one of the best in the tournament and in the world," Silva said of the Australia match.
"When these things happen you start to dream and to think that it's not crazy to think that every time we are a little closer."
While Typhoon Hagidis has wreaked havoc with scheduling in the greater Tokyo area - forcing the cancellation of New Zealand against Italy and England against France - Wales and Samoa will face each other in the relatively calm Kumamoto on southern Kyushu island.
Gatland said he was not concerned about weather issues and his Six Nations champions were "just concentrating on ourselves and hoping to finish on top of this group and then start thinking about the quarter-final".
"Hopefully after Sunday we can think about getting down to Oita and preparing for a Sunday game against France. They will be very tough but we have to do a job this Sunday first."
15 Leigh Halfpenny, 14 Josh Adams, 13 Owen Watkin, 12 Hadleigh Parkes, 11 Hallam Amos, 10 Rhys Patchell, 9 Aled Davies, 8 Aaron Wainwright, 7 Justin Tipuric (captain), 6 Aaron Shingler, 5 Adam Beard, 4 Bradley Davies, 3 Dillon Lewis, 2 Ryan Elias, 1 Nicky Smith
Substitutes: 16 Elliot Dee, 17 Rhys Carre, 18 Wyn Jones, 19 Jake Ball, 20 Ross Moriarty, 21 James Davies, 22 Tomos Williams, 23 Gareth Davies.
15 Gaston Mieres, 14 Leandro Leivas, 13 Juan Manuel Cat, 12 Andres Vilaseca, 11 Nicolas Freitas 10 Felipe Berchesi, 9 Santiago Arata, 8 Alejandro Nieto, 7 Santiago Civetta, 6 Juan Manuel Gaminara (captain), 5 Manuel Leindekar, 4 Ignacio Dotti, 3 Diego Arbelo, 2 German Kessler, 1 Mateo Sanguinetti
Substitutes: 16 Guillermo Pujadas, 17 Juan Echeverria, 18 Juan Pedro Rombys, 19 Diego Magno, 20 Manuel Diana, 21 Agustin Ormaechea, 22 Tomas Inciarte, 23 Rodrigo Silva.