Manchester City midfielder Kevin de Bruyne has suffered a knee injury ahead of Sunday's Premier League clash against Huddersfield Town, the club said on Wednesday.
The 27-year-old Belgium international had joined City squad last week after helping his country progress to the World Cup semi-finals in Russia.
He came off the bench on Sunday in City's 2-0 victory over Arsenal in their opening Premier League match.
"Kevin De Bruyne is undergoing tests on his right knee after sustaining an injury at training on Wednesday," the club said in a statement. "The extent of the problem is not yet known."
In 2016, De Bruyne missed 12 games after injuring his right knee during a League Cup semi-final victory over Everton.
De Bruyne scored eight goals and made 16 assists as City lifted the league title with record-breaking 100 points last season.
Arsenal suffer Kolasinac, Maitland-Niles injury blows
Arsenal defender Sead Kolasinac and midfielder Ainsley Maitland-Niles have been ruled out until October with injuries, the Premier League club has said.
Kolasinac, 25, sustained a left knee injury in a pre-season match against Chelsea earlier this month while Maitland-Niles was substituted off in the first half of Arsenal's 2-0 defeat by champions Manchester City in their opening league fixture.
The 20-year-old Maitland-Niles has a fracture to his left fibula. Defender Carl Jenkinson has also suffered a sprain on his right ankle and will be out for upto two months.
"Sead has a left knee injury. We are aiming for him to return to training in October," Arsenal said on their website.
France international Laurent Koscielny, who missed his nation's World Cup-winning campaign with an Achilles tendon tear, is on the mend and is expected to return to training in November.
Arsenal have been boosted with striker Danny Welbeck and defender Nacho Monreal participating in full training ahead of Saturday's league match against Chelsea.
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