Manchester City captain Vincent Kompany faces another spell out of action after aggravating a calf injury just eight minutes into his comeback, manager Manuel Pellegrini revealed after his side's 4-1 thrashing of Sunderland.
Belgium centre-back Kompany had missed eight successive matches with the problem before returning as a substitute after 62 minutes of City's stroll at Eastlands on Saturday.
However, he was forced to leave the pitch soon afterwards, leaving Pellegrini with a significant defensive problem ahead of Tuesday's trip to title rivals Leicester.
"Vincent is not the best news. He was ready to return, but I did not want him to play the whole game," Pellegrini said.
"He worked the whole week with normality. We will see tomorrow what the doctor says, but it is the same injury to the same calf."
City have not kept a clean sheet all season when Kompany has been missing, and his absence causes significant concern for Pellegrini ahead of a very busy month.
His side face at least seven matches across three competitions in January following the match at Leicester, and Pellegrini will hope that his captain can make a quick return.
Before Kompany came on, City conceded a sloppy goal to Sunderland striker Fabio Borini, having earlier taken a commanding lead with goals from Raheem Sterling, Yaya Toure, Wilfried Bony and Kevin De Bruyne.
"Of course, I think it is better to win 4-0 than 4-1. Maybe it would have been better to win 7-1 and score more goals but if you tell me now we are going to win all the games 4-1 here this season, then I don't have any
problem," Pellegrini said.
- Severely damaged -Sunderland manager Sam Allardyce had made six changes to the team beaten at Chelsea seven days earlier, but none of those who came in did their first-team prospects much good.
Allardyce's side remain next to bottom of the Premier League, suffering a fourth successive defeat after conceding three goals in the opening 25 minutes.
He felt that the loss of defender Younes Kaboul to a recent hamstring injury has severely damaged his side.
"They were three goals we could have done a lot better with, particularly the first and the third," Allardyce said.
"In the last three games, we have gifted teams goals and found it difficult to come back.
"As much as you change the side around and think you are going in the right direction, in the last three games we have slipped back in the danger zone.
"It is hard work to think what my best team is. It is good to have Lee Cattermole back in midfield but the problem was the loss of Younes Kaboul in defence.
"Until we start getting better defensively, we are going to struggle to get results. That is our big problem as a team.
"We have got a hugely difficult period coming along. We have got players who are saying they deserve a chance in the team.
"Everyone has had a chance now and they have not done as well as they should.
"Now it is my time to make some big decisions ahead of the January window and say: 'Who do we want to bring in and who am I going to move out?'"