Sinclair has struggled with a knee injury, and has just played four of City’s last eighteen matches. His current contract at the club expires in the summer.
Sinclair told the Manchester Evening News: “All the knee needed was the equivalent of an oil change.
“It needed fluids draining, a bit of rest and an injection just to help it with its mechanical functions.
“It feels absolutely great now. I am upbeat and looking forward to getting back. I definitely want to stay here As long as I can stay injury-free and still train and enjoy my football, I don’t want to stop playing here.”