Petrov believes the Villa supporters should be proud of what Barry achieved at the club where he clocked up more than 400 appearances during a 12-year stay after moving from Brighton.
The England midfielder made the £12million switch to Eastlands in the summer after a move to Liverpool collapsed 12 months earlier when the Reds failed to meet the then £18million asking price.
Petrov said: "Gareth deserves a good reception. The Villa fans should be very proud. Manchester City are building a good team, they want to compete at a high level, and they rate Gareth as one of the best midfielders in the country.
"He gave so much to this club and I think the supporters should give him a very good welcome. Every time he came on the pitch he tried to make them happy and gave his best for them.
"He played over 400 games for Villa. I have a lot of respect for players who can do that. Not many players can do that. Only players who love a club can do that and that was Gareth with Villa.
"He is always texting about the club so he still cares. He played a long time here, he just can't forget it, and I hope they give him a warm welcome."
Petrov added: "Gareth went on a high. Not many players can achieve what he did for this club - and he stayed an extra year as well.
"They should welcome him, to show why he was loved all the years he was here."
Petrov is looking for Villa to be more consistent this season and handle the expectation levels after two successive top-six finishes in the Barclays Premier League.
Martin O'Neill's side had reeled off six wins on the trot in all competitions before losing 2-1 at Blackburn last Saturday.
Petrov said: "We know what pressure means. We have had it the last two seasons and we need to cope with it again and be more consistent.
"We have got a style of play now. We know what we need to do. We are solid at the back, strong in the middle and have got strikers who can score goals.
"We need to work hard when we lose the ball. We need to work hard to get it back as soon as possible and we control games more now.
"The experience of being in the top four for much of last season was great and we want the same again."