Libertarianism applied to Clarett

I don't quite see why Maurice Clarett isn't allowed to enter the draft. Basically, the NFL arguments as to why he shouldn't be allowed are weak. I am not a big Clarett guy, but if he wants to go to the NFL before the league believes he is "physically ready," that's his right. We are sending younger men and women to Iraq, after all.
As far as I can figure, the reason he is blocked is because of the NFL collective bargaining agreement (which is the first time I can remember one of those things benefitting a league).
Clarett has a right to be entered, I think.