“It’s going fast, but we have a good group of players. They’ll show up tomorrow, don’t worry – and they’ll be fresh and ready.”

Portugal, ranked 8th in the world, 40 places ahead of Scotland, began their campaign with a 2-1 home win against 12th-ranked Croatia.

“It will be a challenge and we have to improve,” said Clarke.

He reiterated that he thought his team played well defensively against Poland, apart from a few mistakes that led to goals. And he stressed to his players that these mistakes must be avoided, especially against such a high-ranking team.

“In football you have to move on,” said Clarke. “It was a good performance and a very disappointing result. Hopefully a very good performance and a better result this time.”

Cristiano Ronaldo, who scored on his international debut against Iran at the 2006 World Cup in Germany, made headlines when he scored his 900th career goal against Croatia – a world record.

However, Clarke stressed that the 39-year-old, who currently plays for Al Nassr in Saudi Arabia, is just one of many top players that Portugal has at its disposal.

The opposing team’s coach, Roberto Martinez, also stressed that his team was more about “the collective” than about individuals.

The Spaniard is no stranger to Clarke, having led Belgium to victory as national coach in 2019 in Scotland’s first defeat. Even after his time as a player at Motherwell, he continues to maintain very close ties to Scotland.

He met his wife Beth in Lanarkshire, but his father-in-law put national loyalty above family on Sunday.

“I hope I can beat him,” Martinez added. “If I don’t, that would be a bad sign.”