Found this in an article in a business publication, of all things:
One data point that all players who are thinking about leaving athletic eligibility behind should be looking at is provided through a free service supported by the NFL. The service is called the NFL Draft Advisory Board, and while it is imperfect, it is free, and should be provided at least some weight by every player who is considering an early exit from their respective universities.
The NFL Draft Advisory Board, made up of NFL scouts and general managers, gives players insight on where they think they may be selected in the upcoming NFL Draft, if selected at all. Again, it should only serve as one data point for athletes considering to leave school early.
So, as I read this, Johnson can ask the board for an opinion, and it does not impact his eligibility. That makes it a no-brainer. get the free evaluation, and maybe get some feedback on what you need to work on to improve your draft position. Can't blame a guy for wanting to consider all options for his future. (and future income).
On the flip side, if the board says he might go in the top 4 rounds (probably not likely, but you never know), then that might make it a 50-50 decision, depending on financial issues/need.