You will make few million dollars (let say US$3 million a year) a year but you will pay a heavy price in return. I just watched a documentary, it stated that the life expectancy of an average football player is like 55 (at least 20 years less than average population). I surf the web and all the websites say pretty much the same and most of the players have lot of problems after retired.
The the question is, given what you know and if you have the ability to become one, would you go for it? If you are not going for it, then let assume it's not the end of the world. You still have a stable job that you can earn US$30,000-US$50,000 a year and live a normal life. I personally wouldn't go for it given what I know of the consequences. Money is very important to me, but life is more precious.
*Note: I thought they were lucky that they can become a football player with lot of fans and making millions a year. I didn't know that they have the heavy price to pay.