According to the NFL, in cooperation with the NCAA, he wasn’t eligible to declare for the draft, he had to return to Georgia and continue playing, for no money beyond tuition, room and board.
He decided to try and make a little money off of his fame, taking $3,000 in exchange for autographing a bunch of memorabilia. For this, he was suspended by the NCAA for 4 games. (Never mind how much the university was making off of him and his jersey.)
In his first game back from suspension, he continued to show why many thought he was the best running back in the college football, until the 4th quarter, when he tore his ACL.
Now, he will probably still get drafted if he decided to come out of college this season, but probably not as highly as he would have last year, costing him a few million, I’m sure. Money he could have had, if the NFL and NCAA didn’t block players who aren’t 3 years removed from High School from declaring for the draft. It’s mind-boggling that the league is allowed to have a rule that, in effect, blocks adults from making money in their chosen profession, and blocks individual teams from paying them for it.
If a kid wants to come out, and a team wants to draft him, why does the league get to interfere with that commerce?