Following back-to-back weeks in which Miami Dolphins quarterback Tua Tagovailoa suffered apparent head injuries, the National Football League (NFL) and the NFL Players Association (NFLPA) agreed that the rules around how teams handle head and neck injuries needed to be revisited.

Before games began Sunday, the League confirmed that it had accepted recommendations made by the NFLPA, and the updated rules went into effect immediately.

The new rules change the role that the team doctor and the onsite non-affiliated neurologist play in determining whether a player can return to the field after exhibiting certain motor skill deficiencies, such as stumbling.

In the past, doctors would consult and run a series of tests to determine if the behavior — known as ataxia — is related to a neurological injury. Now, regardless of the nature of the injury, a player seen stumbling will be ruled out automatically.

The first player to deal with the new rules was Miami’s Teddy Bridgewater, who was starting in place of Tagovailoa while that player worked his way through concussion protocols. On the first offensive play for Miami, Bridgewater was hit in the endzone after throwing a pass, and his head made contact with the turf.

“Basically, what happened was a spotter saw [Bridgewater] stumble, and under the new rules and changes, he is ruled out and placed in the protocol,” said Mike McDaniel, Dolphins head coach, per CNN. “He doesn’t have any symptoms, and he’s passed his evaluation, but he’ll be now under the new regulations in the concussion protocol.”

Whether the loss of Bridgewater was a major factor in the Dolphins’ defeat last Sunday is debatable, but they were not the only team that saw the new rules impact the play of the game.

Facing off against the Atlanta Falcons, Tampa Bay quarterback Tom Brady dropped back to pass on a play late in the fourth quarter. Brady was tackled by Grady Jarrett for what would have been a drive-ending sack, but referees tossed a flag.

The ensuing “roughing the passer” penalty allowed the Buccaneers to run out the clock, ending any chance of a late Falcons comeback. On review, the sack appears to be a legitimate tackle without any sign of intent to injure; however, referee Jerome Boger — who threw the flag — stated on Monday that he saw the tackle as “unnecessary.”

Tom Brady addressed the possibly game-saving penalty, simply saying, “I don’t throw the flags.”

The NFL and NFLPA released a joint statement about the updates to the policy on Friday. The League also released the results of an independent investigation into the Miami Dolphins and whether the team followed the proper procedures in addressing the injury to Tagovailoa.

“The NFL and the NFLPA agree that the outcome of [the Tagovailoa case] is not what was intended when the Protocols were drafted,” the report writes.

The policy contains a list of “mandatory ‘no-go’ symptoms” which would preclude the player from continuing to participate in the game, reducing the possibility that medical staff, coaches, and players would allow a player exhibiting such symptoms to return to the field.