Manchester City striker Sergio Aguero is a huge doubt for his side's Premier League meeting with Arsenal later this month.
The Argentine limped off as a result of a hamstring injury during the champions' 3-0 win over Stoke City on New Year's Day having netted his side's third goal.
The £38m forward has already been ruled out of City's FA Cup tie with Watford on Saturday, but could be out of action when they face Arsenal on January 13.
"It's difficult to assess an injury like that but my experience says he is doubtful for Arsenal," said assistant manager David Platt.
"There will be a lot of swelling in there and a bit of bleeding and we will not know for 48 hours how long he will be out for."
Aguero confirmed the problem on Twitter, saying: "It was great to end and start the year with a win. Too bad about the crick when we were wrapping up the game.
"I have to take a 48 hour rest and have some studies done on the injury. I'll keep you posted. Thanks for the support!"
Aguero has netted 10 goals so far this season.