The 33-year-old Bulgarian announced his retirement earlier this month having spent over a year out of the first team, battling acute leukaemia.
Petrov is in remission and has been charged with helping Cowans nurture Villa's future talent.
"I'm very excited by this new challenge and I wish to thank the Club and the manager, Paul Lambert, for giving me the opportunity to continue my association with Villa, which I have always regarded as a privilege," Petrov said on the club's website.
"I will study for my coaching badges over the coming months and I am looking forward very much to working with Gordon Cowans, someone I know and respect, a true Villa legend.
"My hope is that I can assist Gordon through my own experience in the game and that I can help the young lads to progress, become better players and better human beings. There are important values that we have always stood for at the club and we will continue to do so.
"As I have said several times recently, the club has been amazing with me, from the fans to the chairman, Randy Lerner, the chief executive, Paul Faulkner, the manager and the players, as well as staff at Bodymoor and Villa Park.
"The main thing for me, however, is that it is not for sentimental reasons that I will be taking up this role but because I have something to contribute and I really want to do this.
"The manager allowed me to sit on the bench on Sunday at Wigan so that I could get some perspective from the coaching and management side. I travelled with the team and was able to see close-hand and from a new viewpoint just how the first team prepares for a game and he many elements during a game. I'm looking forward to imparting some of my knowledge and continuing to learn as I grow into the role."
- Sports & Recreation
- Gordon Cowans
- Paul Lambert