Will Bosnia & Herzegovina secure an immediate return to League A, or can Montenegro, against the odds, climb into the box-seat?
Back in June, these two played out a 1-1 draw in Podgorica; Luka Menalo giving the visitors the lead, before Adam Marušić equalised.
Overall, Bosnia are unbeaten in Group B3, drawing both away games and claiming all three points in both home matches.
Last time out, the Golden Lilies beat Finland 3-2 in Zenica, thanks to Miralem Pjanić's penalty and then Edin Džeko’s brace.
So, Ivaylo Petev’s team kick off top of the group, knowing a victory would rubber stamp promotion.
This is the third edition of the Nations League, with Bosnia gaining promotion to League A in 2018, before being immediately relegated again two years later.
Given their current position, this Norwich-esque yo-yoing looks set to continue.
Although, Montenegro kick off just one point below their hosts, knowing an unlikely away win would leave them in the catbird seat to go up.
The Brave Falcons beat Romania home and away in June, memorably winning 3-0 in București in their most recent international.
Stefan Mugoša bagging a hat-trick at Stadionul Rapid-Giulești.
So, Miodrag Radulović's team have proven that they’re capable of springing a surprise on the road, but a victory here would be even more memorable.
Will Bosnia be celebrating promotion back to League B following this one at Stadion Bilino Polje?