The hosts will be relegated if they lose and Poland avoid defeat to Portugal - or if they draw and the Poles pull off a shock win - while their visitors are closing in on a place in the quarter-finals.
Match preview
Though they battled against the odds to finally put a first point on the board last month, Scotland had previously followed their dismal exit from Euro 2024 with three straight defeats at the start of their latest Nations League campaign.
Steve Clarke's side lie bottom of Group 1 and are in distinct danger of heading straight back down to League B, even if successfully scrapping for a rare clean sheet earned them a gritty 0-0 draw with leaders Portugal last time out.
That result may have relieved some of the pressure on Clarke's shoulders, but Scotland are still enduring their longest ever winless run on home soil (six matches) and also their longest streak without a competitive victory (10).
In fact, failure to take maximum points on Friday night would see them equal their worst winless sequence overall, drawing level with a nine-game run set back in 1998.
It could have been a very different story, as conceding late goals against Portugal and Poland cost precious points, while Ryan Christie's first-half strike in October's reverse fixture was overturned by a Croatian comeback in Zagreb, where Che Adams had a potential equaliser chalked off by the VAR.
Now, at least four points will be required from their final two fixtures if Scotland are to defy the drop - and even finishing third would result in a relegation playoff.
While Croatia have never won in Scotland - as they prepare for their first trip to Hampden since October 2013, when they lost 2-0 in a World Cup qualifier - goals from Igor Matanovic and veteran striker Andrej Kramaric secured victory over the Scots last month.
Three days later, Zlatko Dalic saw his side miss out on sealing both second spot in Group 1 and a place in the quarter-finals, as they let a two-goal lead slip against Poland and had to settle for an eventful 3-3 draw.
Having started with defeat in Portugal and a home win over the Poles, the 2023 Nations League runners-up have accrued seven points thus far, and that has them on the brink of qualifying for the knockout rounds again.
If they win in Glasgow - or even if they draw and Poland fail to defeat Portugal - Croatia can wrap up progress with one game to spare, as their growing fondness for UEFA's newest international tournament continues.
Only Greece have won more games across the last two editions of the Nations League, which actually represents quite a turnaround, as Dalic and co had lost seven of their first 10 matches in the competition.
Croatia have also scored in each of their last 14 away games all told, averaging just over two goals per game in the process, so they can head for Glasgow confident of breaching their hosts' leaky back line.
Scotland Nations League form:
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L
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D
Scotland form (all competitions):
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L
L
L
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D
Croatia Nations League form:
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W
W
D
Croatia form (all competitions):
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D
L
W
W
D
Team News
After lamenting the loss of several experienced players to injury over the past few months, Scotland will welcome back Jack Hendry, John McGinn and Stuart Armstrong this month, though they must do without Torino striker Che Adams.
The latter missed last week's Derby della Mole against Juventus with a thigh injury and has not yet recovered, so Tommy Conway, Lyndon Dykes and Lawrence Shankland will all vie to start up front.
None of the trio are in top form though, as Conway has scored five goals for Middlesbrough, Dykes has yet to find the net in League One, while Shankland has only one goal to show for his efforts this term following an excellent 33-goal haul for club and country last season.
Whoever is selected should receive support from McGinn and Scott McTominay, whose Napoli teammate Billy Gilmour is set to pit his wits against Croatia's playmaking maestro Luka Modric in midfield.
The visitors will be missing Lovro Majer and Bruno Petkovic due to injury, but Modric skippers an experienced squad also featuring Ivan Perisic: the PSV Eindhoven winger has been directly involved in three goals in two games against Scotland but has never scored across 18 Nations League appearances.
As first-choice goalkeeper Dominik Livakovic is suspended after being sent off versus Poland, Augsburg's Nediljko Labrovic should deputise between the posts on Friday, when Scotland's 41-year-old stopper Craig Gordon will continue to stand in for the injured Angus Gunn.
Scotland possible starting lineup:
Gordon; Ralston, Souttar, Hendry, Robertson; McLean, Gilmour; McGinn, McTominay, Doak; Dykes
Croatia possible starting lineup:
Labrovic; Sutalo, Caleta-Car, Gvardiol; Perisic, Modric, Kovacic, Sosa; Baturina, Kramaric; Matanovic
We say: Scotland 1-1 Croatia
Croatia can afford to play with a certain amount of freedom, as qualification is within their own hands, while Scotland are feeling the weight of public expectation.