German second-division leaders Stuttgart say Kevin Grosskreutz has been hospitalised after getting involved in a fight on Monday night.
The club said in a statement that "Grosskreutz is doing well in the circumstances. It looks like he can leave the hospital again on Wednesday. Kevin Grosskreutz will file charges after the incident."
Stuttgart did not give the extent of the 28-year-old right-back's injuries.
Police, who did not name the player, reported that a 28-year-old was taken to hospital with a head injury after receiving a punch in a fight between two groups.
A 16-year-old from the same group was also taken to hospital, with no apparent external injuries. Four suspects were arrested.
Grosskreutz, then playing for Borussia Dortmund, was an unused substitute for Germany's 2014 World Cup-winning team in Brazil.