riverripper
I think it is very hard to get in but you can do it if you are super motivated, have the right background, and are lucky. I know from my class someone is going to the Cubs and someone is going to the NBA for the summer. Off the top of my head Kellogg alums in pro-sports, CEO of the Bears, VP of the NFL, VP/assistant GM of the White Sox, some MLB big wig, a kid a few years ago ended up at the Indians, a few high ups in the NBA and the NHL. I am a diehard sports fan but it has to be one of the toughest places in the world to break into. Very few people do it, and I think very few do it straight out of school.
I think with the NFL, Kellogg has great brand awareness because they run a bunch of programs tailored to the athletes. They do mini-mba's for the league. Heck, Eddie George is actually an EMBA here. I would say top schools might get you noticed but if you really want sports, you are probably better off in law school...unless you want marketing or something like that.
I would agree with riverripper wholeheartedly. If you really want to succeed in either a league office, representing a labor party, office of the GM for a pro team, or representing the players themselves, you're probably better suited to get your law degree and enhance your knowledge of labor law, and contractual law. However, also like riverripper said, these organizations are massive marketing machines as well, and a place like Kellogg could really serve you in that regard.