LONDON Dec 16 Manchester City's Germany midfielder Ilkay Gundogan has suffered a cruciate knee ligament injury, the club said on Friday.
He is likely to be ruled out for several months.
"It's so so difficult for him, it's sad for him," manager Pep Guardiola told a news conference.
"We're going to miss him a lot, it's unlucky, but that's football.
"Now we need him to feel we are there and wait and come back safe. He's going to be operated (on) and be back as soon as possible."
Gundogan joined City from Borussia Dortmund in June and was just settling into the side when he sustained the injury during Wednesday's 2-0 win over Watford.
Fourth-placed City host Arsenal, who are one place and one point ahead of them, on Sunday. (Reporting by Steve Tongue, editing by Ed Osmond)