The NFL’s chief medical officer said all proper examinations and checks were administered Sunday when Indianapolis Colts quarterback Jacoby Brissett was cleared to return to a game against the Pittsburgh Steelers, only to be placed in the concussion protocol following the game.

Dr. Allen Sills said Brissett received multiple sideline evaluations, from both team officials and the unaffiliated neurotrauma consultant during and after the game.

“It doesn’t mean someone didn’t do their job or a mistake was made. You are always going to have people that present an hour, six hours, 12 hours, 24 hours later with symptoms.” Sills said on a conference call. “All of our protocols were followed. … We need to continue our quest for better diagnostic tools.”

Sills said 379 concussion evaluations have been performed during NFL games this year, including preseason games. He could not compare that number to recent years, but said he wants that number to be high.

“We want to be very aggressive in our screening,” Sills said.