Speaking at the start of a Head, Neck and Spine committee meeting, Dr. Allen Sills made clear that the league will react aggressively to data that showed a 16 percent rise in concussions in 2017. There were a total of 291 diagnosed concussions in 2017 -- including preseason, regular season and postseason games -- compared to 250 in 2016.

Some of that total can be attributed to higher levels of self-reporting by players. In 2017, 47 percent of concussions involved a player addressing symptoms with a medical official, the highest percentage on record. But Sills told committee members that self-reporting data shouldn't be used as a shield. One of his first PowerPoint slides asked how concussion numbers can be reduced "IMMEDIATELY."

"It's not OK," Sills said, "to simply stand behind that and say, 'Well, the numbers are going up because we're doing a better job.' I think to me this is really a call to action to see what we can do to drive it down."

Tuesday's meeting, which the NFL allowed a handful of reporters to view for about 30 minutes, was the start of a process that will follow three specific paths to reduce concussions:

• Increasing the use of what the NFL considers safer helmets;

• Decreasing preseason concussions by pointing out warning signs to individual teams;

• Work with football operations on style of play.

Overall, 9 percent of NFL players suffered diagnosed concussions in 2017. That averaged out to about 0.7 concussions per game and about nine per team. The numbers were exceptionally high during training camp practices, both before and after the start of preseason games, and overall rose 73 percent during that time period compared to 2016. Most occurred during what the NFL identified as "scrimmages" during practice.

Dr. Thom Mayer, the NFL Players Association's medical director, proposed each team's coaching staffs receive concussion education and training, in part to help them understand the impact of specific drills and practice schedules.

"With 291 concussions," Mayer said, "if we're going to take a progressive strategy toward reducing or eliminating the maximum number of concussions we have, I think it's imperative, and I think we're long past having coaches educated as to how these concussions occur. Not only the head coaches but also the position coaches. I think we have to get down to that level for them to understand precisely how these concussions occur.

"I get that there are 80 guys flying around trying to make the 53[-man roster], but I think we also owe to ourselves and to our players to take an aggressive education program to those coaches and assistant coaches."

Also Tuesday, the NFLPA distributed a 107-page medical playbook to players. The document provides details on concussion prevention, detection and recovery, among other health topics. It also includes information about chronic traumatic encephalopathy (CTE), suggesting players be vigilant but rational about it.

"The most important advice is not to assume you have a chronic, irreversible disease simply because you have symptoms," the playbook tells players. "Consult an expert in this field who can do the comprehensive neurologic evaluation and studies necessary to determine your status and the best treatment for it."