The NFL and the players' union have found no evidence of deviation by New England's medical staff from the league's concussion protocol regarding Tom Brady last season.
League spokesman Brian McCarthy said in a statement Wednesday that Brady released his medical records for review as part of the process. McCarthy said the review also identified no evidence that Brady sustained a concussion or reported signs or symptoms consistent with one in 2016.
The NFL and the NFL Players' Association completed an evaluation of film of every Patriots game last season, as well as reports from independent neurotrauma consultants and spotters assigned to those games.
Brady's wife, supermodel Gisele Bundchen, told "CBS This Morning" in May that Brady played through a concussion on his way to a fifth Super Bowl title. Brady said in August he preferred to keep his medical history private, adding that he wasn't blind to issues such as chronic traumatic encephalopathy, or CTE, the debilitating brain disease that can cause a range of symptoms, including memory loss.
"I really don't think that's anybody's business, what happened last year, and I'm focused on this year and improving and working on things I need to get better at," he said at the time.
Brady, who turned 40 last month, hasn't missed a regular-season game because of injury since tearing a ligament in his left knee in the season opener in 2008. The Patriots open the season Thursday night at home against the Kansas City Chiefs. He is expected to become just the 13th quarterback since the 1970 merger to start an NFL game after turning 40.
Brady sat out the first four games of the 2016 season as punishment for his role in the "Deflategate" scandal. He missed practice late in the season for leg, thigh and ankle injuries.
But he wasn't listed on the league-required injury reports for a concussion or head injury at any point during the 2016 calendar year or for the playoffs.
A recently released study by the brain bank at Boston University found evidence of disease in the brains of 110 of 111 former NFL players it examined. It linked repeated head blows as the culprit, in what is the largest update on CTE.
Brady said last month that he stays up to date on such studies, and he tries to learn from athletes who came before him.
He added that he is secure in the ways he goes about protecting himself from injury on the field.
"I'm confident in what I do," he said.