The NFL has warned teams that 11-on-11 training camp drills were responsible for last year's spike in preseason concussions.
The league has stopped short of banning full-squad drills, which coaches consider essential to preparing for the contact that occurs during regular-season games. But NFL data showed that preseason concussions in 2017 increased by 73 percent, from 26 in 2016 to 45.
Jeff Miller, the NFL's executive vice president of health and safety initiatives, said Friday that he hopes the data "will inform what clubs do" when camps open. Miller said the league hopes to replicate its success in addressing a similar issue after the 2014 season. In 2015, camp concussions dropped by 33 percent.
"We didn't have a level and specificity of data then," Miller said, "but we went through a process led by our football operations to inform teams and talk to them and say, 'Hey, we noticed this data.' We brought it to their attention, and there was an effort by many of them to address the question. And we saw a drop the following year.
"Raising the consciousness level of that issue was definitely worthwhile. I don't want to take full credit for that decrease, but I think it informed what clubs did."