After being attacked in the heart of Vienna, Austrian football star Guido Burgstaller suffered severe head injuries, including a fractured skull, according to a statement released by his club Rapid Vienna on Monday.

Rapid Vienna said that throughout the weekend, the 35-year-old striker was hit by an unidentified person and fell, hurting his head. The incident happened in front of witnesses.

Burgstaller, who has made 26 appearances for Austria’s national team, is scheduled to be in the hospital for “the coming days” and will probably be out of action for several months, according to the club.

The club stated that it want to protect Burgstaller and his family’s privacy and provided no other information on the incident.

It further stated that it “trusts that the responsible authorities will soon bring the as-yet unidentified perpetrator to justice.”

In addition to his accomplishments on the international scene, Burgstaller has played in Austria, Germany, and England. In two stints, he made the most club games for Rapid Vienna, although he also made 95 appearances for Schalke in the Bundesliga and three for Cardiff City in the Championship.