Ah, yes, a psychobabble question for a profession that wouldn't seem to figure much one way or another in terms of personality traits: the professional football player.
Or does it???
There's a fascinating article (OK, I hope that doesn't reveal too much about my personality...) in the Milwaukee Journal Sentinel about what makes a player tick. And, also, whether that factors in much to personnel decisions. It makes for good reading, particularly the differences between the various player positions on a team as described by the players themselves. There are also a couple related articles you can find in links adjoining the article that provide further background on this topic. It's worth checking out.