https://phys.org/news/2018-07-great-nfl-conundrum-injury.html

As ESPN Monday Night Football analyst and former NFL head coach Jon Gruden explained, "The less time we spend meeting, the less time we spend practicing, the less time we spend together practicing like we're going to play on game day, the less we're going to execute, the less we're going to be disciplined and the less we're going to perform."

But the most hard-hitting criticism of all came from New England Patriots Coach Bill Belichick; far from preventing injuries, he believed the rules encouraged them. "You have a gap between preparation and competition level," he told the Associated Press. "And I think that's where you see a lot of injuries occurring. We get a lot of breakdowns. We get a lot of situations that players just aren't as prepared [for] as they were in previous years, in my experience anyway."