Antonio Cromartie, star player for the San Diego Chargers was fined by the NFL for commenting about the team's nutrition, saying that "nasty food" was to blame for the Chargers' poor performance last year.
In a tweet last Friday, : "Man we have 2 have the most nasty food of any team. Damn can we upgrade 4 str8 years the same ish maybe that's y we can't we the SB we need. [sic]"
The tweet came on the same day the team had a meeting about not using Twitter in a way that would be "detrimental" to the squad. Many other teams in the league have followed this route and enacted similar rules for Twitter.
Cromartie was informed by his head coach Norv Turner of the fine. He called the $2,500 charge "a bit excessive".
The NFL is presently formulating a broad policy to ban players from using social media platforms, including Twitter, during games.
The move follows suggestions that the controversial and often-fined Cincinnati Bengals player Chad Johnson, known for his excessive touchdown celebrations, would be tweeting on the sidelines during games.
The US sports network ESPN has also banned its news staff from using Twitter to tweet about subjects that don't serve the network in anyway.
The policy also includes blogs or any other form of social media.
The guidelines are for ESPN on-air reporters and writers, and if violated could result in suspension or dismissal.
The news was picked up when on-air National Basketball Association (NBA) presenter Ric Bucher tweeted: "The hammer just came down, tweeps. ESPN memo prohibiting tweeting info unless it serves ESPN.
"Kinda figured this was coming. Not sure what this means but my guess is I can still tweet about my vacation/car shopping, etc. Which I will do, if I can. But the informal NBA talk is prob in jeopardy.
"I'm probably violating some sort of policy just by telling you. In any case, stay tuned."
In the UK last week departing Tottenham Hotspur striker Darren Bent used Twitter to hit out at the club.
The player, who is expected to leave Spurs before the start of the new season, posted about his impatience with the transfer process and his club's chairman Daniel Levy.
In one post, Bent said: "Do I wanna go to Hull City NO Do I wanna go Stoke NO do I wanna go Sunderland YES so stop fucking around Levy."