In addition to the financial penalty, UEFA ordered Freiburg to play their next home match in UEFA competition behind closed doors.
Under UEFA's disciplinary regulations, clubs are held responsible for the behaviour of their supporters at European fixtures.
Aston Villa accepted responsibility for delays across nine Premier League fixtures during the campaign.
During the World Cup, specialist technology will monitor social media for violent, threatening, abusive or discriminatory posts aimed at England players and relatives.
Atlético reportedly value Álvarez at his €500 million buyout clause and have shown no interest in negotiating a sale.