The NFL's best tight end took himself out of practice back in mid-August. He didn't play in any of his team's preseason games. That in itself wasn't all that notable, since he hasn't played in the preseason since 2012. He has subsequently returned to practice, but he's been limited in all his appearances, and on Thursday he told reporters that he's not 100 percent.

Rob Gronkowski pulled up with a hamstring injury during a joint Patriots practice with the Chicago Bears and, well, it's apparently still bothering him quite a bit. According to a subsequent report from NFL Network's Ian Rapoport, it's "no sure thing" that Gronk suits up for the Pats' season opener against the Arizona Cardinals on Sunday Night Football.

New England will already be without Tom Brady due to his four-game suspension and pass-catching back Dion Lewis due to a second surgery on the knee he injured last season. Not having Gronkowski would be a major blow to the prospects of success for Jimmy Garoppolo, who will be filling in for Brady while he sits.