Rob Gronkowski is a 23-year-old single male who loves to have fun and provide entertainment for the masses. The Gronk is a party animal. That’s no secret. Taken at face value, it’s hard not to appreciate and enjoy someone who so thoroughly enjoys life. But then you watch the TMZ video of the Patriots tight end at the XS nightclub in Las Vegas on Sunday night, dancing shirtless on stage and lifting up a presumed friend and slamming him to the ground, wrestling-style. This might seem like harmless fun, except Gronkowski was using his recently re-repaired broken left forearm to help hoist his friend up and over. According to a source close to Gronk, he didn’t appear to do any more harm to the forearm, which was in a long black cast. But you still have to sit back and wonder what he was thinking He probably wasn’t thinking about minicamp in June, or training camp in July. Because taking a chance with that arm and yet another setback puts him at risk for getting back with his team in time for those camps. He probably wasn’t thinking about quarterback Tom Brady, who sorely missed his presence during that AFC Championship loss against the Ravens. Brady is going to need him to be healthy and in the lineup going forward to help the offense keep from being stifled by certain defenses. Gronkowski probably wasn’t thinking about team owner Robert Kraft, who agreed to hand over $54 million with a six-year contract extension. He probably wasn’t thinking about New England fans, who pay good money in hopes of watching him play every week. He probably wasn’t thinking about Bill Belichick’s famous words to every player: “Do your job.’’ With that contract comes a certain responsibility to the team. Gronk can still have fun; he just can’t do things that may put him at risk. His job also includes keeping himself injury-free during the offseason. Using a recently repaired broken arm to bodyslam someone falls into the category of not acting in the most responsible manner.