Since 1858 football has been a much loved contact sport played by strong and well built men. If girls were to be allowed to compete with men, the whole game would be changed and not for the better. There are many reasons why girls should not play at a professional level with men. Including that of tradition, fatal injuries, and its not just football that can not be played professionally with a mixed team but its most if not all sports. Physiologically, physically and emotionally males and females are different. Although women an be very skillfull and athletic, their physical attributes do not match up to male counterparts when it comes to football or in addition to any other sports. .
There is no reason why girls can't play football, however they should definitely be limited to girls-only teams. Imagine the outrage if a male player was to shirt front or tackle and severely injure a female. The male player would become a target for fans for physically injuring a female. In addition can you name many men that are comfortable with tackling a female. Meaning that they would not be playing their best and the whole standard of their game would be lowered. There are enough female competitors around so that females can competitively play football against each other. .
Furthermore, there are also strong safety reasons against the idea of girls being on a mixed field. Its very difficult to play the way you would in a female-only team or a male-only team as its easy to get injured. Football is a contact sport and on the field there are no allowances for size. A male playing against a female during a game of football could result in serious injury to the female. .
The three most common injuries found in a high school mixed football team are general trauma(29.3%), strains(21.7%), and sprains(27.4%). In addition, severe facial trauma would not be tolerated by a female where as some men are quite proud of their football "battle scars".