City snapped Sinclair up from Swansea City in 2012 with the intention of helping his potential to flourish as part of a star-studded squad.
The 25-year-old winger has, however, found first team football and top form hard to come by.
A blood clot kept him sidelined in 2013 and a season-long loan at West Bromwich Albion last term failed to bring about an upturn in fortunes as he once again found himself frozen out.
Another move had been mooted during the current transfer window, but Sinclair has figured for City in pre-season and believes his career is heading in the right direction.
He said in the Manchester Evening News: “This is probably one of the best pre-season’s I’ve had. The minutes I’m getting now, I haven’t had that.
“I feel great, you can see it in the performances. I’m scoring goals, I’m getting back to my normal self, how I was at Swansea.
“Pre-season is probably the most important time for any footballer, to get those games, and I feel great and hopefully now I can get more minutes and be ready for the season.
“As a player you’ve got to go through the tough times, and the last 18 months have been a very, very tough time for me - going on loan and getting injured and also having my blood clot the previous year.
“Like I say, all I can do is look forward, play what’s in front of me, and whenever I get the opportunity I’ve got to produce and get the goals whenever I can and just keep playing well.”
Watch Liverpool take on Manchester City in the International Champions Cup on Thursday morning - kick off is just after midnight, live on Sky Sports 1.