A place in history is at stake as the national side attempt to qualify for the knock-out phase of a major tournament for the first time ever.
Scotland will progress to the last 16 if they claim the three points in their final Group D fixture, which will be easier said than done againt a Croatia side who were World Cup runners-up only three years ago.
Clarke’s biggest selection dilemma centred around replacing Billy Gilmour, a stand-out in the 0-0 draw at Wembley on Friday, who is ruled out after being placed into self-isolation following a positive Covid test on Monday.
Here is the starting XI he has selected for the biggest match the country has faced in decades ...
9. AMC - Stuart Armstrong
Gilmour's replacement in the starting XI, the Southampton man made a late sub appearance at Wembley after starting against the Czechs. His will be the one charged with supporting the front two and driving forward with the ball. Photo: PAUL ELLIS
10. CF - Che Adams
Has shown what he brings to the team in a game and a half - and notable by his absence early on against Czech Republic. Adams will be key to Scotland's hopes and though he has yet to score (as they all have) he's found the right positions. Photo: JUSTIN TALLIS
11. CF - Lyndon Dykes
Physical presence will be required against strong defenders of Croatia and will give Dejan Loveren a battle - while winning flick-ons for Adams or knock-downs for Armstrong. Is due a goal. Photo: PAUL ELLIS