If Johnny Manziel is able to convince an NFL team he's worth taking a risk on, he will be forced to sit out the first four games of next season.
Per Seth Walder of the New York Daily News, the NFL has suspended Manziel four games for violating the league's substance abuse policy.
NFL Network's Ian Rapoport noted Manziel is not out of the NFL's doghouse after the four-game suspension:
Johnny Manziel's 4-gm suspension only applies to substance abuse. If he signs, he's subject to the personal conduct policy (his legal case)
— Ian Rapoport (@RapSheet) June 30, 2016
That said, there doesn't appear to be a lot of faith among NFL front offices that he will play in the league again, per Benjamin Allbright of CBS Sports:
Asked 22 NFL front office guys if Manziel would ever play in NFL again.