The final act of this international window comes on Tuesday when Slovenia arrive at Hampden (19:45 BST), a chance to make up for last week's nightmarish experience against the Swiss, a game reduced to a non-event after Jack Hendry's early red card. Scotland battled away, but lost 3-0.

A "sore one", he says. "We had to suffer for a good 80-90 minutes," he explains. "That can take its toll mentally but we showed how strong we are going into North Macedonia.

"It will mean a lot for the squad, for the manager to come back home and put on a good performance and finish the camp with a win. You need to keep building on that. That's the standard that we want to set."

Welsh's story starts at Celtic, a product of their academy who turned down overtures from Udinese and Toulouse in his time. He wanted to stay and fight for his place but it was all stop-start.

After making his debut in the spring of 2020, Celtic kept signing centre-halves - Carl Starfelt and Liam Scales, Cameron Carter-Vickers and Yuki Kobayashi, Moritz Jenz and Maik Nawrocki, Gustaf Lagerbielke and Auston Trusty.

He played 70 games in total. It wasn't enough. "It's not easy but at a club like Celtic, they always want to improve, bring in more players because that keeps the competition," Welsh says. "It's football. You're not guaranteed to play even though you want to.

"For your boyhood club, to play every game, would have been the best-case scenario. Unfortunately, that didn't happen. I'm a big boy, I can accept that players are going to play in front of you. That's fair enough."

Challenging years, though. A time for mental fortitude. "That's probably the thing that people don't see," he remarks. "What you need then is a good support group around you, good family, good friends. My agent was excellent for me. They just need to be there. That's the main thing, just be there.

"Psychologically, it can affect players but I don't think it affected me too much. I never took anything personally. That's just the way it goes. The best players, technically, probably don't [always] get to the top. It's the players that are mentally strong.

"Look at John [McGinn] and Robbo [Andy Robertson]. The mentality that they have. They're obviously fantastic footballers but it's the mental strength as well. To churn out performances every week, to turn up in good shape, to be ready to play tactically, technically, physically and mentally. That's the biggest challenge."