Novak Djokovic retired injured after losing the first set 7-6(5) against Alex Zverev on Friday to put the German through to his first Australian Open final.

But, regardless of how you feel about him or what you think about him bowing out, nobody — not even Novak Djokovic — deserves to be booed for being injured. You don’t have to like him. You can absolutely root against him. You can boo him when he’s healthy.

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.