Too many men with too many players on the court. Under no circumstance can any player or coach be ejected on a technical foul caused by too many players. In gridiron football, if a team has more than the allowed number of players on the field during a play (eleven in America, twelve in Canada), the offending team is penalized five (American) or ten (Canadian) yards for "too many men on the field" (also called "twelve/thirteen men on the field"). This is usually the result of an improper substitution. The 2009 Grey Cup game in the CFL was decided on a too-many-men call.
Health issues in American football to field condition. Because American football is a full-contact sport, head injuries are relatively common. According to the San Francisco Spine Institute at Seton Medical Center in Daly City, California, up to 1.5 million young men participate in football annually, and there are an estimated 1.2 million football-related injuries per year. An estimated 51% of injuries occur during training sessions, while 49% occur elsewhere. Injuries are nearly 5 times more likely to happen during contact training sessions than in controlled, non-contact sessions. Older players are at the most risk for injuries, while teams with experienced coaches and more assistant coaches