Rapid Vienna's Austrian striker Guido Burgstaller suffered significant head injuries during an attack in Vienna at the weekend, the club said on Monday.
Burgstaller, who previously played with Cardiff City and Schalke 04, is in his second spell at the club and has made 26 appearances for Austria.
"The 35-year-old was attacked by an unknown man in Vienna's city centre and suffered a fracture of the base of his skull after a fall triggered by a brutal blow," the club statement said.
"Burgstaller was immediately examined and treated in detail in a Viennese hospital. Unfortunately, he will have to spend the next few days there and he will not be able to practice his profession for several months."
Burgstaller made his most recent appearance for Rapid in their 3-1 loss at Omonia Nicosia in the Conference League last week, and the club's next game is at home to FC Copenhagen on Thursday in the same competition.
The club, third in the Austrian Bundesliga standings going into the winter break, are ninth in the Conference League, guaranteed at least a playoff place going into the last game of the league phase and could still claim an automatic spot in the last 16.
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