I tried to make this case a few years ago here on the Alley and was shot down. It seems(ed) to me that having dreads, long dreads in particular, would be a hindrance in football. The added weight when they are wet from perspiration and the fact that they would seem to make you feel weighted down, give imposing players something to grab and help retain heat on 90 degree days.
http://www.thepostgame.com/baltimore-ravens-player-loses-3-4-pounds-haircut?
http://www.thepostgame.com/baltimore-ravens-player-loses-3-4-pounds-haircut?