If NFL contracts are anything like NFL contracts, I'm pretty sure there is some sort of general clause in there that states that can take some sort of action if a player does anything to 'degrade the reputation of the league or it's member clubs'. I doubt they'll ACTUALLY be able to do anything or really pursue it unless they REALLY wanna get him outta here.
But just cuz it ain't spelled out in the contract don't mean shit.
Same way they got Donald Sterling outta here. There was no 'You can't say racist things in private' clause in his shit.
You do know the HUGE ASS difference between the 2 right?
Sterling was the one that said that racist shit. In order for that example to be even remotely valid, the NBA would've had to have Sterling sell his team for something his wife or kids or brother said or did.