This does raise an interesting sidenote. Notwithstanding NCAA rules, or the unnecessary injury risk, I think it would be awesome if NCAA football teams could schedule secret scrimmages with NFL teams. Same goes for college basketball and the NBA.
Given the secrecy of the event, select donors for the college teams, and dedicated premium season ticket holders for NFL teams, could sign an NDA and be offered the chance to purchase tickets at ultra-premium prices. College teams, having faced off against pros, would find themselves at a huge advantage. Pros would get a bonus based on secret ticket sales, along with the pleasure of beating up on lesser competition.