Bulgarian Petrov spent three years at the City of Manchester Stadium after they paid Atletico Madrid £4.7 million for his services in July 2007. He went on to play in 59 Premier League games for City and scored nine goals for them.
He never appeared to figure in the plans once Roberto Mancini replaced Mark Hughes as manager and it was no surprise when they decided against offering him a new deal at the end of the season.
He didn't feature at all after February but news that he's a free agent has alerted clubs in a number of European countries. Petrov has indicated that he'd prefer to remain in England and is set to have a medical at Bolton.
It seems that the deal is still some way off but he's a player Owen Coyle is very keen to bring in as he builds his own squad of players.