Novak Djokovic has reacted to the crowd at the Australian Open booing after he decided to retire from his semifinal against Alexander Zverev. The Serbian tennis player, 37, had taken to the court with his left leg heavily taped following Tuesday’s injury.

Spectators booed as the 37-year-old Djokovic walked off toward the locker room, and he stopped, turned around and responded by giving two thumbs-up.

Novak Djokovic’s quest for a record 25th grand slam title has been cut short at the Australian Open after he stunningly retired from his semifinal match due to a left leg injury.