Manchester City defender Sun Jihai will have to wait to make his comeback after suffering a setback in his recovery from a long-term hamstring injury.
Sun Jihai signed a new deal with Man City in May
The 29-year-old has not played this season but was thought to be close to returning to fitness.
City boss Stuart Pearce said: "We are still waiting to find out the precise nature of the problem.
"It is serious to the extent he has been out for four months with the same injury and it is still not right."
Pearce also revealed that City striker Darius Vassell is targeting the home game against Middlesbrough on 30 October for his comeback after a knee injury.
The former Aston Villa frontman has not played since August.