If an athlete gets a "Once in a lifetime" opportunity; such as being drafter to the NFL; instead of the traditional 5 year commitment, they can do a 2 year commitment on active duty, then a set amount in the reserves. It's not just been for football players either. The military gets their money's worth out of the individual in 2 ways. Time serving in the reserves, as well them being a recruiting tool. As much as many might want to say that that is not necessary, the truth is, our young people are still very much impressed by sports figures, actors, pop stars, etc... And such an individual as a graduated cadet, does make for a very good recruiting tool. Both for officer and enlisted. And there are names from all branches of the service that have had such opportunities. David Robinson of the NBA went to Annapolis. Point is, these individuals, which are VERY VERY RARE CIRCUMSTANCES, do make up their commitment. 2 years active duty, then a set amount in the reserves.
And for what it's worth, it's not one of those: "Hey, I want to go to the NFL, NBA, etc..." We're talking about a team that invited an individual that a team was impressed enough to invite to their summer camp (After graduation); check them out; if they still want them, sign a pseudo contract that says the team will wait 2 years until the active duty commitment is over. Then, they will be auditioned again in 2 years (Which is what Chad Hall is doing right now), to see if they are still as good as they were 2 years ago. Then, if the team is willing to give them a "Contract", then the military (Already in the loop all this time), may grant the release from active duty and into the reserves.
FWIW; these rules continually change. It's been this way for a while in the air force. Until recently, the army allowed such once in a lifetime opportunities, to be taken advantage of directly out of the academy. In other words, directly to the reserve with no active duty time. But that changed a couple years ago to be more in line with the other services.
Also; FWIW; I can't remember the young lady's name, but a few years back, after graduating the academy, she auditioned for "Tops in Blue". Sort of like the air force's "American Idol". While on tour for that, a promoter/record deal/type of opportunity was presented to her. She was allowed to go reserves to take advantage of this once in a lifetime opportunity. It's also been made available to enlisted individuals who were offered some sort of once in a lifetime opportunity partially through their enlistment.
Again; these opportunities are extremely rare. These aren't individuals who are putting their name into the NFL draft because they want to. These are are individuals where teams, agents, etc... are coming to them and saying: "You don't need to go through the draft... You're one of the best of the best; and we want you". Extremely rare. But it does happen. And these individuals definitely help the military services out with publicity, recruiting, serving 2 years active, and reserve service. I know there's some people who aren't too keen on academy athletics; or even college athletics at all. Many think it's a waste of money and time. But the truth is, athletics brings in a lot of money to a school; even the academies. And once in a while, you get an athlete who happens to be one of the best of the best. Me personally, I think it's a reasonable compromise. The military gets their payback. The military gets an excellent recruiting aid. The individual fulfills their commitment. And the individual gets to fulfill a once in a lifetime opportunity.