Scotland are without Hickey at these championships and his loss is wounding at right wing-back, but what ails Clarke’s side is bigger than just one absent player.
This is about a soft underbelly appearing where before there was resilience. This is about doubt replacing certainty all over the pitch.
And it’s about Clarke trying to pull off a feat of psychology as much as a feat of coaching against the Swiss.
It’s about personnel and structure, but it’s also about mindset at this point.
They’ve just been pummelled. By turns, they themselves have spoken about an embarrassment and a humbling.
Callum McGregor has apologised to the fans, who have been nothing short of extraordinary, even by their jaw-dropping standards.
McGregor said on Saturday that Switzerland will smell blood – and they will.
He, and others, have spoken about the need to stick together and stay strong. Wednesday will be the test of that.
Clarke has done many excellent things as Scotland head coach. He has fixed problems that looked unfixable, he has won matches that for a generation looked unwinnable, he has taken Scotland to tournaments that looked out of reach.
He did it over time, but he doesn’t have any time now. Wherever this team’s fearlessness has wandered off to, it needs to find its way back.
The soft touches need to become hard cases again.
