Johnston was part of Canada’s second World Cup finals appearance since 1986 and the 24-year-old full-back’s performances did not go unnoticed as he will move to Celtic in January.
Postecoglou’s side moved in the transfer market early to offset the potential loss of Josip Juranovic after attempts to extend his contract fell flat before the World Cup break.
Miller confessed that he has seen a lot of Johnston and feels that the Canada international ticks all the boxes expected of a modern full-back.
“I’ve seen a lot of Alistair and I like what I see”, Miller told the Daily Record.
“He’s everything you would expect in a modern full-back.
“He certainly enjoys joining in the attack, is quick and aggressive as hell and will get stuck into challenges.
“He has a terrific attitude, a very humble guy and is smart too.”
Johnston is a versatile operator, who has also slotted in at centre-back for his soon-to-be-former club Montreal, and recorded four goals and assists apiece from 33 games in the recently concluded Major League Soccer season.
Miller believes that Johnston will suit a Postecoglou side owing to his comfort in possession and his consistency.
“I asked a couple of staff members this week what he was like and they said he is a great team-mate, just a good lad to have around the dressing room”, Miller added.
“I’m sure he will suit an Ange Postecoglou team.
“He’s very consistent.
“The fact Celtic maintain a lot of possession on the ball then it’s important he is clean with the ball. And he is.”
Celtic will travel to Aberdeen on 17th December when the Scottish Premiership resumes, with the Hoops enjoying a nine-point lead over rivals Rangers.
