However, the Bulgarian has pleaded for the new Villa boss to be given time to make his mark.
McLeish met the Villa players en bloc for the first time on Friday when they reported back for pre-season training.
Petrov knows all about his new boss from when he was playing for Celtic and McLeish was in charge of Old Firm rivals Rangers, and has no doubt about his quality.
He said: "I met the new manager a few days ago but I know him from before also and I'm really glad we have someone like him in charge of our team.
"He's a man who is a bad loser, he likes to win and he likes to be on top of everybody. I think we need a man like this.
"The chairman (Randy Lerner) is aware of his ability and what he can do and I think he's the right choice of person to lead this club.
"He needs to be given time. Everyone deserves time and he'll prove to be the right man for this job, no question. He's got that will to win."
McLeish built a strong team spirit at Birmingham and has stressed the need for a similar scenario at Villa.
He will also give a fresh start to the likes of Stephen Warnock and Stephen Ireland, who seldom featured under Gerard Houllier.
Petrov said: "He made it clear today that you need a united team and a strong dressing room and he will give everyone an equal chance from the start of the season.
"Even the guys who didn't play a lot last season, they're back and they were training with a smile today."
Petrov believes McLeish's desire to be a success will rub off on Villa and is playing down the significance of his move from across the city.
He said: "I know the gaffer from the time I was at Celtic and he was Rangers manager and I know his passion about winning.
"I know his passion to build a team that is going to compete with the big clubs. He's got a chance to build a team here.
"People who have been talking about him moving from Birmingham City here to Villa, you know what, I don't think that matters at all.
"He's our manager now, we're behind him and we're going to play for him. We want to move the team forward for him and that's what he wants to do for the club."
Petrov added: "He had a brief conversation with us this morning, he said he trusts every one of us and he's going to make us better.
"That was enough for us as players, to know the manager is completely behind us.
"We'll be behind him also and we will work hard to improve and to be as good as we can possibly be.
"A lot of people would have wanted to come here as manager. I'm not surprised because we have a very good team and Aston Villa is a big and prestigious football club.
"I know the chairman wants the manager here to be a winner because he wants winners, that's what we're geared up for here."