Well the ambiguity is "defender" meaning "a player on the defending team" and "a player with the role defender". Actually the second interpretation could have

Well the ambiguity is "defender" meaning "a player on the defending team" and "a player with the role defender". Actually the second interpretation could have an interesting effect, since it also doesn't specify team. So if the attacking team puts one of their defenders in the circle the defending team is out of luck.