The 35-year-old is considering other options, one of which is retirement to start a career in coaching.
But there has also been interest from across the Atlantic, with Toronto, coached by fellow Scot Mo Johnston, and New York Red Bulls, who number former City team-mate Claudio Reyna and fitness coach Juan Carlos Osorio among the familiar faces.
"One thing I don't want to do as a player, at whatever level, is overstay my welcome," he told the Manchester Evening News.
"I will be the first one to admit when I cannot do it anymore.
"I still feel I have something to offer as a player but I want to go into coaching eventually and I will need to do the badges because that is important."