Manchester City's Samir Nasri is expected be sidelined for a month after manager Manuel Pellegrini revealed the French midfielder needs surgery on a groin injury.
Nasri missed the Premier League champions' 7-0 League Cup victory over Sheffield Wednesday in midweek due to the problem.
And after confirming the 27-year-old former Arsenal star will not feature in Saturday's league match at Hull, Pellegrini said: "It's serious because maybe he will have surgery in the next days.
"I'm not a doctor but I think he will be out for around one month.
"He was training but he wasn't 100 per cent. He didn't feel comfortable with what he was doing so the doctor decided that was the best option.
"Of course he's a very important player for us and it's not easy for us to play without Samir.
"But I never give excuses about players that, for different reasons, are not in our squad. We have an important squad."
City are also currently without Brazilian midfielder Fernando (groin) and Montenegro striker Stevan Jovetic (hamstring), although Pellegrini said of the pair: "Both of them, I think, will be ready next week."