The 21-year old midfielder has made just six appearances for City since joining from Everton in the summer but will not be able to add to that tally until 2013.
"I've just had a little bit of a setback with my hamstring injury. It will probably be another few weeks, so I'm looking into the new year," he told the club's official website.
"I'm doing quite a lot of training at the minute though, so I'm keeping busy.
"It's down to strengthening now, so I'm doing a lot of work in the gym and am just getting it right to prevent another injury.
"It's been a frustrating start to the season and to my City career, bit I'm focused now and I'm ready to get back."