Wales manager Chris Coleman has promised they "will take it to Bosnia" as they seek to secure qualification for next summer's European Championship.
Coleman's side need a point against Bosnia-Herzegovina in Zenica on Saturday night to end the nation's 58-year wait to play at a major tournament.
Even if Wales lose they have the safety net of welcoming group minnows Andorra to Cardiff on Tuesday night, but Coleman insists he wants to get the job done in the Balkans.
"We're ready and we will take it to Bosnia," Coleman said.
"This will be a tough game because it's Bosnia's last chance to go for that third play-off spot.
"Sometimes with success comes complacency, but not with this group of players.
"They've been highly focused all week on the next job, the next challenge, and that comes against Bosnia."
Coleman confirmed that star forward Gareth Bale will start against Bosnia, even though he has played only 24 minutes for Real Madrid since hurting a calf over three weeks ago.
But Coleman did add that it was unlikely Bale would play the full 90 minutes against Bosnia or Andorra.
"We have had no information (from Madrid) that Gareth can only play 30, 45 or 60 minutes against Bosnia," Coleman said.
"We do not take chances with players and Gareth will start. If he was a doubt that he could not start then he wouldn't.
"We know there is a lot at stake but we would not risk him. He is fit to start, but I am not sure he is fit enough for 90 minutes.
"We will monitor how it goes as we have two games in four days, which is tough, so he is unlikely to play 90 in both.
"But he has looked good in training and we have had no limits on how long he is able to play."
Bosnia have been beset by problems with doubts remaining over Edin Dzeko, who injured a calf two weeks ago.
Dzeko trained on Friday but the Bosnia coach Mehmed Bazdarevic admitted he did not know whether the Roma striker would be fit enough to play against Wales.
Everton midfielder Muhamed Besic is suspended after being sent off against Andorra last month and Tino-Sven Susic misses out through injury.
Wales captain Ashley Williams would have to mark Dzeko but he said his only focus was on the team's performance, and not who he could possibly be coming up against.
"Our focus is on ourselves as always," Williams said.
"We want the game to come but it's important to enjoy it. We've worked so hard for it and we're anxious to get on the pitch.
"The lads are not scared at all, they have been like that all campaign. There will be no fears and we're not unsure what to do, and with that comes confidence.
"As a squad we've gained a lot of caps playing in all kinds of games and we can definitely draw on that experience.
"It's nice when you look around the team there's a lot of experience around you."