Easier to do when you're an extremely relevant person in your sport.
Not all NFL athletes have a shot at getting any endorsements at all. In fact, most don't.
Be a star player or famous role player on a very successful team, that's way different than some backup lineman who is out of the league by the time their rookie contract ends.
American football is by and far the worst culprit - in all the other big or semi-relevant american sports - baseball, basketball, hockey, etc, you can make a decent living playing overseas. Not huge, but decent enough. Can't do that with football.
Not all NFL athletes have a shot at getting any endorsements at all. In fact, most don't.
Be a star player or famous role player on a very successful team, that's way different than some backup lineman who is out of the league by the time their rookie contract ends.
American football is by and far the worst culprit - in all the other big or semi-relevant american sports - baseball, basketball, hockey, etc, you can make a decent living playing overseas. Not huge, but decent enough. Can't do that with football.