After Chris Henry's untimely passing, Bengals wide receiver Chad Ochocinco wanted to wear Henry's number 15 in tribute. The league said no. The penalty for something like this would likely result in a fine.
The NFL Players Association said that if Chad is fined, then the NFLPA will cover it. George Atallah tweets:
NFLPA will cover any fine levied on @OGOchoCinco imposed by the league and match it with a gift to our Chris Henry memorial fund
PFT writes about the potential problems that the NFLPA could face, due to the appearance that the "union is desperate to find a way to get the public on its side as 2011 approaches" when the existing collective bargaining agreement expires and the league could face a work stoppage.
Meanwhile, the Bengals are caught in the middle of this. The team has full control over the locker room and its contents, and the team can either refuse to give a player a certain jersey or instruct him not to leave the locker room in something other than his assigned uniform.
Likewise, it's possible that the league would prohibit Ochocinco from entering the game wearing anything other than his own jersey.
I get that rules are rules. But sometimes people should just pull their head out of their collective asses and just let one player honor his fallen teammate. There is no harm here and if one believes it sets a precedence, then perhaps people running the show aren't qualified enough to actually apply the exemptions that actually exists in life.