Allen Sills said in a conference call with reporters Tuesday that "about 37 percent" of the 379 concussion evaluations during the preseason and regular season have been "initiated by a self-report." Sills said it was about 20 to 22 percent a year ago.
He called that increase "a positive development."
Sills also said the rules for checking for a concussion were followed properly for Indianapolis Colts quarterback Jacoby Brissett on Sunday, when he was allowed to return to a game after a hit to the head. After the game, it was determined he did have concussion symptoms.
Sills says it is impossible to "capture 100 percent of concussions."
NFL spokesman Joe Lockhart said on the call that the league and the players' union are still reviewing whether the Seattle Seahawks properly followed concussion protocols with quarterback Russell Wilson on Thursday night.
Sills also said data from the last five years shows that the injury rate per game "is actually lower" for Thursdays than games played on other days of the week.
Some NFL players think the league should get rid of short work weeks because they are detrimental to their health and safety.
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