Sinclair has made only 17 appearances since being signed by former manger Roberto Mancini for £6.2million in the summer of 2012 and spent an equally fruitless loan spell at West Brom last season.
"It has been very frustrating for the last couple of years," he told Sky Sports.
"I have tried to do as well as I can in training and hope to get a chance but at this moment in time it is hard for me to get a game.
"There are some world class players here so I can't do much more than keep working hard in training.
"I don't feel I've had the best of chances; I just want to get out there and show why City bought me but I've not had that opportunity.
"I made the decision (to move to City) and I have to deal with it, I can't look back and say it was a mistake but the only thing I do miss is playing football.
"I made the decision to come to City and fight it out with all the big players and it hasn't really worked out this far.
"All I can do is re-evaluate in January and go from there."
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