Valencia midfielder Mehmet Topal will spend up to a month on the sidelines after picking up a shoulder injury in UEFA Champions League action this week.
The Turkey international fell awkwardly during Valencia's Group E opener against Genk on Tuesday night, which ended in a goalless draw.
Medical tests have since confirmed that Topal has suffered a muscle tear in his right shoulder and the midfielder has been told to rest.
The 25-year-old will undergo further examination on the injury in 10 days' time, when it will be decided whether he requires surgery.
The problem is expected to rule Topal out of Valencia's next two Champions League games, against Chelsea at the end of the month and at Bayer Leverkusen on 16th October, as well as at least five Primera Liga matches.