Steve Clarke admitted selecting John McGinn over Ryan Christie for Scotland's World Cup opener against Haiti was the hardest decision of his career.
After 28 minutes, the decision was justified.
Christie dropping to the bench was the only change for Scotland from the final warm-up match against Bolivia, with McGinn his replacement in the midfield.
Ahead of the match, Clarke had stated the call was the biggest he had to make on his starting line-up and urged McGinn to prove his worth.
Speaking to the BBC, Clarke said: "I'm not sure it's a night for big speeches because everybody knows what we're here for and we'll be ready.
"The biggest decision was John McGinn over Ryan Christie, probably the hardest decision I've ever had to make in my managerial career, to leave somebody like Ryan out of the starting XI.
"He accepts it, obviously disappointed not to play and now John has to show why I picked him.
"We've been trying to build experience. There's over 900 caps in this squad. This will be a difficult game, we know that, but let's hope we've got everything right tonight."
