Robert Page insists Wales will forget Sunday’s World Cup to try to stay in the top flight of the Nations League.
Wales remain bottom of the A4 division after losing 2-1 to Belgium on Thursday.
But Poland’s 2-0 home defeat by Holland means Wales can beat Poland in Cardiff on Sunday.
Wales boss Page said: “It’s a final. Forget the World Cup, that’s the game we want to win on Sunday.
“We just have to rescue the boys. There will be some changes and we will create a team to win the game.
Captain Gareth Bale is likely to start on Sunday after coming on as a second-half substitute in Brussels.
Bale has had just one training session, having arrived at camp from the United States late on Tuesday after playing for Los Angeles FC the previous day.
When asked why Bale didn’t start, Page said: “All the traveling. The time shift that is returning is hard work for players to get used to.
“Throwing him straight into an away game against Belgium would be crazy.
“It was good for him to get a few minutes after the jet lag
“It was a wise decision not to play from the start, but I really wanted to get in and help the team as soon as possible.
“This is a great lesson for us. We were without five players who would make us stronger.
“Lessons were learned here for the World Cup. I told them in the dressing room that we asked for it.”
“By qualifying for the World Cup we want to compete against nations like Belgium or Holland and we were there until the end. It speaks volumes for this group of players.”
Page cheered Brennan Johnson after the Nottingham Forest forward gave a glimpse of his talent by setting up Kieffer Moore’s second-half header.
After the majestic Kevin De Bruyne and Michy Batshuayi gave Belgium the lead, Johnson launched a labyrinthine 40-metre dash before delivering a superb cross to the far post.
“Brennan was amazing, he accomplished so much in such a short amount of time,” Page said.
“I asked something different from him, in midfield.
“When you see him running with the ball, that’s brilliant, that’s his game, that’s his strength.”
Belgium coach Roberto Martinez was sent off for possession in the last few seconds.
Martinez said: “First time I’ve been sent off. A new experience.
“I was surprised. I probably should have let the ball go.
“We’ll see what that means, but I’ll respect the referee’s decision.”
Belgium visit leaders Holland on Sunday and Martinez said: “It’s the perfect game to prepare for the World Cup.
“This World Cup could be the best in terms of individual performance and mental freshness.”