I'm not here to write about the merits or demerits of veganism, but what I do know is that NFL athletes put considerable amounts of stress on their body when they train and play. They create micro-tears in their muscles and need protein to repair themselves. This is also the Arian Foster that had hamstring issues last season.
But who knows? There are certainly some athletes, football players included, who have abstained from eating animal protein and animal-related products. You'd be surprised at this list, too. Some of these guys are household names.