When asked if the 21-year-old would start, the Scotland manager responded: "I think it's pretty obvious, don't you?"
Souttar has already played for the tartan army at U17, U19 and U21 level, and it appears he will receive his first senior cap in the friendly on Friday.
McLeish also said that newly-appointed captain Andy Robertson was "absolutely inspirational".
"It is a brilliant story. He has been playing at the top level in the last year. He hasn't only nailed his position - he has got better and better," McLeish said.
"Every week I see him on television he is making goals from left, right and centre. He is almost like an extra attacker. But for the man himself, for young players, it is absolutely inspirational.
"For players who were told at nine and 10 - and I don't know why that happens sometimes - that they will never make the grade and get scunnered by the game and walk away from it.
"Andy has been the epitome of never-say-die, and never-give-up, which is a kind of Scottish trait. He kept going, he persevered and became the player that he is, but he also carries himself well in the dressing room."