The missing Kieran Tierney effect blows a hole in Euro 2024 masterplan as back 5 could lead to pain in Spain

All eyes will be on the teamlines tonight as Steve Clarke looks to make things work without one of his key lieutentants.

Anything but defeat against Spain will send Scotland to Euro 2024 and the size of the occasion means Kieran Tierney's injury could hardly have been timed worse. The Arsenal defender, on loan at Real Sociedad, is out until December with a fresh hamstring injury and it means he won't play for his country again this year.

An injury almost anywhere else on the pitch could be legislated for with a like-for-like sub, but the nature of Clarke's back five depends on Tierney and his left-sided pal Andy Robertson being available. The system has been built round their partnership down the left flank, one running while the other stays and the've developed a telepathic understanding that completely blew Spain away at Hampden back in March.

After five wins from five to start qualifying and qualification for Germany on the brink, Clarke is a national hero these days. But it was just a year ago he was under serious pressure ... largely because of his failure to adapt to Tierney's absence.

That Euro 2020 defeat to the Czech Republic should have been the lesson that a back five doesn't work unless Tierney and Robertson are in on the left hand side. That was proven again against Denmark in the opening World Cup qualifier when he experimented with Robertson on the right hand side ... something that thankfully hasn't seen the light of day against since.

For more than a year after that, Clarke still rigidly stuck to Plan A when one of them were out. He tried it against Ukraine 12 months later, and then again against Ireland. With Jack Hendry deployed in the Tierney role for the latter, a 3-0 thumping in Dublin proved the