As part of the ending of the lockout, the NFL apparently came to agreement with the NFLPA not to suspend all but eight players for conduct during the lockout. One of those eight players, according to a report originally from Pro Football Talk, is the Bengals' Cedric Benson. He was arrested during the lockout and he was just informed that the NFL is suspending him three games (likely because they consider him a repeat offender).
Benson, of course, is appealing the suspension and has now pointed the finger at the NFLPA filing an unfair labor practice charge with the NLRB, according to Pro Football Talk. Benson has a good argument with both the NFL and NFLPA.
First, it is, in my opinion, inappropriate for the league to suspend players for things that they did when they were locked out. If the league wants to lock them out from, among other things, their paychecks and health insurance, then they shouldn't hold them accountable for their behavior.
Second, the NFLPA wasn't a union during the lockout which means they couldn't be negotiating on Benson's behalf. So the idea that the NFLPA came to an agreement on the possibility of discipline for Benson, despite not actually representing him, is part of Benson's argument.
If the NFLPA agreed to discipline for Benson (they say they haven't waived their right to appeal) when they didn't represent him then I think Benson has a strong case here.