HOUSTON (AP) — The NFL and the players’ union announced a series of changes Friday to the way potential concussions are handled during games following an ugly incident in which Texans quarterback Tom Savage was allowed to return to the field after a hit left him on the ground, arms shaking.

Houston Texans quarterback Tom Savage (3) is checked by a referee after he was hit during the first half of an NFL football game against the San Francisco 49ers, Sunday, Dec. 10, 2017, in Houston. Savage left the game. (AP Photo/Eric Christian Smith)

A joint review by the NFL and the NFL Players Association was prompted by the Savage injury. He was hurt in the second quarter of Houston’s 26-16 loss to San Francisco on Dec. 10 when he was driven to the ground on a hit by Elvis Dumervil. Replays showed Savage looking dazed after his head hit the ground with both of his arms shaking and lifted upward. He was taken to the medical tent where he stayed for less than three minutes before returning to the bench and going back in for the next series.

Savage threw two incompletions on that drive, and Houston’s team doctor approached him after he returned to the sideline at the end of that possession. He was then evaluated again and taken to the locker room after it was determined that he did have a concussion.

The NFL said the Texans would not be fined for the incident. The NFL and the union review determined that the medical staff followed protocol but that his return to the game was “unacceptable.”

Medical staff didn’t see slow-motion video where Savage’s “fencing posture,” indicative of a concussion, until after they did their initial evaluation, the review found. Texans medical staff later identified symptoms that weren’t present during the first evaluation.

Among the changes detailed by the NFL and NFLPA (all of them already implemented):

• Using a centralized, unaffiliated neurotrauma consultant at the league office to monitor feeds of all games and contact the team medical staff on the sidelines if they see anything that deserves further evaluation.
• If players show signs of a seizure or fencing responses, like Savage did, they will be removed from the game and cannot return.
• Players who stumble or fall when trying to stand will require a concussion evaluation in the locker room.
• Officials, teammates and coaches have been told to take injured players straight to the medical staff for evaluation if a concussion evaluation is warranted.
• All players who are evaluated for concussions on game day must have a follow-up evaluation the next day by a member of the medical staff.
• A third, unaffiliated neurotrauma consultant will be added to all playoff games including the Super Bowl to step in if one of the other two are away from the sideline tending to an injured player.