Gardner's brother Craig told him to expect a helping hand from Petrov and the teenager has not been disappointed.
"Stan is a quality guy and a great player," Gardner told the Birmingham Mail.
"He scores goals too. He's a top player to partner in the centre of midfield and a top-quality skipper too.
"He takes his job as captain very seriously and he does it brilliantly. He talks to all the lads on and off the pitch. He talks you through the game.
"That's what you need and Stan is definitely a leader out there. He's a top guy."