How do Scotland fill Tierney void for Hungary decider?
Euro 2024, Group A: Scotland v Hungary
Venue: MHPArena, Stuttgart Date: Sunday, 23 June Kick-off: 20:00 BST
Coverage: Watch on BBC One, listen on BBC Radio 5 Live and BBC Radio Scotland, live text commentary on BBC Sport website.
How do you solve a problem like Kieran Tierney? Or more to the point, a lack of him?
Scotland's crusade for a spot in the last 16 of Euro 2024 comes to a dramatic head against Hungary in Stuttgart on Sunday, but they must do battle without the dynamic presence of the Arsenal defender.
With Tierney having pulled up with a hamstring injury against Switzerland, does Steve Clarke go for a straight swap in a back five, or does he take this as a chance to shake things up?
We asked BBC Sport Scotland pundits Leanne Crichton and Steven Thompson for their thoughts...
How big a miss is Tierney?
Given one of the reasons Clarke plays the system he does is to crowbar Tierney and fellow left-back Andy Robertson into the same team, pretty seismic.
The Arsenal defender has not had his injury problems to seek, having already missed three months this season while at Real Sociedad with various leg issues.
But, in Cologne Stadium on Wednesday, his influence was clear to see, particularly going forward.
In the graphic above, you can see how pivotal Tierney - number six - is to the team in an attacking sense.
The average position graphic shows his high line, which allows Robertson - number three - to really push on compared to Jack Hendry and Anthony Ralston on the other side.
Here, we can see just how strong the left side of Scotland's play is through the team.
This starts with Tierney tucking in behind Robertson to allow the latter to bomb forward, knowing there is cover behind.
Tierney is also known for going forward himself, including that rampaging run last year against Spain for Scotland's second goal in a 2-0 qualifying victory.
In terms of statistics this tournament, the 27-year-old was coming into his own before he was injured on Wednesday.
He has enjoyed an 85% passing accuracy rate, a 100% clearance success rate, while he also enjoyed 101 periods of possession with the ball.
So what now?
Change the formation?
Former Scotland midfielder Leanne Crichton believes the misfortune of losing Tierney could offer Clarke an opportunity to tinker with his formation.
So much of the structure of the back line is because of Tierney and Robertson.
It maybe weighs heavily towards the option of going to a back four, otherwise you're forcing people into positions they may not be wholly comfortable with.
The whole point of the back five was to accommodate Robertson and Tierney, and also if you had the attacking power of either Aaron Hickey or Nathan Patterson on the right. You don't have them either.
Anthony Ralston is a right-back. Is there an option to go back to the four, then?
It's a bit of a dilemma for Clarke. But with it comes positives.
Middle to front, changing the shape would give you a lot of strength and would allow you to maybe get Stuart Armstrong or James Forrest in there to play off a front three.
Tierney is a leader. But, when you take him, you do so knowing he's one of the most injury prone players we've had in the last decade. We've had to play an awful lot of games without him.
Scott McKenna came on against Switzerland and he gives you balance.
Obviously he's not got the attacking attributes Tierney does, but that's tournament football. You need to be prepared.
A straight switch with McKenna?
Former Scotland striker Steven Thompson believes we already witnessed who will fill Tierney's boots when Scotland walk on to the pitch in Stuttgart on Sunday.
I think what will happen is Scott McKenna would just come in.
He's a decent replacement and is a very good player. He offers us an aerial threat in both boxes for set plays.
I doubt the manager would deviate from the shape he plays and McKenna will just slot in.
It's obviously a major blow with Tierney going out, he's one of our best players. His combinations on the left with Robertson have been a big feature for the national team under Clarke.
You have to feel for him. He's had an a horrendous time with injuries. It's absolutely devastating for him.
It's a once-in-a-lifetime opportunity and, now his tournament is over, it's 10 times worse. Especially now they've got the opportunity to be the first Scottish team in history to get out of a group if we get the result we're desperately after.
But the team has to kick on and react.
They've had a lot of adversity to deal with in terms of injuries, plus the red card for Ryan Porteous in the first game against Germany was a curve ball.
But they can't afford to think about that. Ultimately, there's a job to do.
