Manchester City have been hit with the news Carlos Tevez is set to be out for two to three weeks.
The Argentina striker suffered a knee injury in the weekend's World Cup qualifying defeat by Brazil and had been expected to be out of City's home game with Arsenal on Saturday.
But it has now been confirmed that the ex-Manchester United man is almost certain to miss next week's Manchester derby.
The 25-year-old is desperate to play against his former club, having assumed cult hero status at Old Trafford before making a bitter departure this summer and quickly becoming a fans' favourite at City.
Blues boss Mark Hughes will therefore give Tevez every opportunity to prove his fitness in time for the 20th September clash.
"The Argentine medical people said it would be two or three weeks," he said.
"We think it might be less than that but he is a doubt for the derby next week.
"However, we will do everything in our power to get him fit because, for obvious reasons, he would love to play in that match."
The £25million man could also miss City's Carling Cup third round tie against Fulham on 23rd September and the Blues' home game against West Ham, another of his former clubs, on 28th September.
City's Brazilian star Robinho aggravated an ankle problem in the same World Cup game, which Brazil won 3-1 to leave Argentina struggling to qualify.
He is set to have a scan on the injury and is a major doubt as big-spending City aim to maintain their winning start against the Gunners.
"He had a little bit of swelling on the ankle," Hughes added.
"We do not think there is a significant injury there but it is best to check to make sure there is no stress fracture.
"Once we get the results we can decide whether he plays (on Saturday) or not."