Gronkowski was videotaped earlier this month performing a wrestling move on a friend at a Las Vegas nightclub despite having a broken forearm in a cast.
"I know we are referring to Gronk and partying and doing wrestling moves and stuff. I think Gronk's having fun," Mankins said Tuesday during a charitable appearance at the Kraft Family Blood Donor Center.
In the week before the Super Bowl, he said his arm feels "all right" and noted that he has a lot of time to heal and there is no rush. He said the goal is to be 100 percent by the time camp starts.
Mankins, one of the Patriots' captains and a senior presence in the locker room who often sets the tone for teammates, said at least his boisterous teammate isn't breaking the law.
"The headlines might not be what a lot of people want, but at least he's not getting DUIs or doing things that are against the law. I don't think he's hurting anyone.
"Hopefully he doesn't hurt his arm because then that would be bad. You know Gronk, he is a big meathead that likes to party and play football. I think that's what he's doing.
"When he starts breaking the law, then that would be definitely something we'd have to look into," he said.