Boyd had endured a difficult start to the campaign and was roundly criticised for his profligacy in front of goal in the opening matches of the season before answering his critics by breaking his duck in last week's 7-2 win over Falkirk.
And any lingering doubts about a crisis of confidence were banished last night when he came off the bench to grab the winner in Aberdeen after just three minutes on the pitch.
"People were always looking for something more, something extra. But these guys will put the ball in the back of the net and players like that are few and far between.
"I had hoped the substitutes would make an impact and Boyd more than did that. It was a great goal."
Boyd's goal tally for Scotland has been impressive and McLeish added: "Six goals in 10 games is a great record and the competition is intensifying for front places.