Chris Wathan
BBC Sport Wales
The Nations League climax could mean the world to Wales – with the route to North America in 2026 dependent upon it.
Manager Craig Bellamy has hailed the competition as the perfect testing ground for his new era, with the real ambition to lead his country to a major finals.
But the path to the World Cup in two years' time is intertwined with Wales' fate over the next two games – and perhaps beyond, with play-offs now a possibility in the Nations League's revamped format.
And how Wales finish this current campaign could even decide when their road to 2026 begins.
What's changed?
In past years, teams could only win Nations League promotion by finishing top of their group – as Wales did in 2020 to earn a place in League A.
Now there is a second chance via the play-offs with teams finishing second in League B taking on teams finishing third from League A over two-legs. The winners will secure a spot in the top-tier for the next Nations League in 2026-27, with the losers placed in League B.
Similarly, there are also new relegation play-offs, with the teams third in their groups in League B playing-off against the runners-up from League C groups.
The current state of play
Wales are currently second in Group B4 heading into the final two matchdays. Standing on eight points, they are two points behind leaders Turkey and four points ahead of third-placed Iceland – both of whom they face next.
With two wins over Montenegro and a draw each against Turkey and Iceland, Wales cannot finish bottom and so cannot be directly relegated to League C.
Defeat to Turkey on Saturday means Wales cannot finish top and will be guaranteed a place in either a promotion or relegation play-off.
Anything other than a Wales win means Turkey would have to drop points in their final fixture in Montenegro on Tuesday if Bellamy's men are to have any chance of finishing top.
Regardless of the result in Kayseri, if Iceland lose to Montenegro in Saturday's other fixture, Wales are certain of finishing at least second.
Why does it affect the World Cup?
The expanded, 48-nation 2026 showpiece in Canada, Mexico and USA may seem like a long way off, but European qualifying begins next year – the draw for which is set to take place on 13 December.
And where Wales finish in the Nations League could have two key bearings on how that road to the World Cup shapes up.
Most significantly, finishing top in the Nations League opens up the chance of getting a World Cup qualifying play-off spot.
With an increased 16 teams qualifying, 12 places will be given to the winners of the 12 groups.
There will be four on offer via the play-offs which will involve 16 teams: the 12 group runners-up, and the four best-ranked Nations League group winners who did not finish in the top two of their World Cup group.
In other words, with the majority of Nations League group winners from League A likely to either qualify directly, or earn a runners-up spot, finishing among the top sides in League B puts you in a very strong position to take a World Cup play-off place.
What if Wales don't win their group?
Not only will Wales' World Cup play-off chances diminish – and depend just on that campaign - but the Nations League play-offs mean it could also decide when and how Wales' World Cup campaign will shape up.
Those campaigns are set to take place between March and November 2025, with 12 groups of either four or five teams battling it out.
However, if Wales end up in a Nations League play-off then they will not start until either June or September 2025.
Teams in the promotion and relegation play-offs from League B – as well as the Nations League finalists – will be prioritised to be in a four-team group to start in September.
Put simply, if Wales do not overcome Turkey in the Nations League, their group campaign for the World Cup could well be a six-game shoot-out over two months next autumn, or they face kicking off the campaign with two key games in June at the end of a long domestic season.
Pick your Wales side for Turkey
Choose a formation and Wales XI for Saturday's Nations League game
What happens if Wales finish top?
Wales will be promoted to League A for the 2026-27 Nations League and are likely to start their World Cup qualifying campaign in a five team group in March.
They will also significantly boost chances of a World Cup play-off spot even if they don't finish in the top two of their qualifying group.
Furthermore, being in League A would also give them a very good chance of a Euro 2028 play-off spot – as happened last year under Robert Page when Wales faced Finland and Poland despite finishing third in their qualifying group.
What happens if Wales finish second?
They will face a promotion play-off over two-legs in March, with the home tie first.
Potential League A opponents include Serbia, Hungary, Poland and Belgium.
They are likely to be second seeds in a four team World Cup qualifying group that starts in September – or be in a five-team group that starts in June.
What happens if Wales finish third?
They will face a relegation play-off over two-legs in March, with the away tie first.
Potential League C opponents include Sweden, Slovakia, Kosovo, Belarus and Armenia.
They are likely to be second seeds in a four team World Cup qualifying group that starts in September - or be in a five-team group that starts in June.
The draw for the Nations League play-offs takes place on 22 November in Nyon.