ROSEMONT, Ill. — Troy Vincent recalls going back to the huddle and forgetting to look at the sideline for the play, even though it was his job to relay the signal.

He mentions the days after one concussion when he couldn't remember phone numbers and kept thinking his car was running.

"I'm not sure if we — athletes — know what a concussion is," said Vincent, a veteran defensive back and the president of the NFL Players Association.

The NFL is taking steps to educate players on the subject and make sure they report concussions, implementing a whistle-blower system when training camps start next month.

"It's an important element of what we're trying to accomplish here," NFL commissioner Roger Goodell said Tuesday after a conference with medical personnel from every team in the league. "I have said repeatedly and will continue to say that medical decisions must override any competitive decisions.

"And if anyone feels they are being forced onto the field when they are not ready to play, we want to know about that and look into it."

Although details need to be worked out with the players union, the new system allows anyone to report anonymously when doctors are pressured to clear players or when players are pressured to play. It's one of several changes the league is making in its effort to manage concussions.