Tua Tagovailoa Rule? NFL, NFLPA reportedly working on change preventing players' return after 'instability'

The conversation dominating the NFL following Tua Tagovailoa's concussion during "Thursday Night Football" appears to be leading to a rule change.

The NFL and NFL Players Association are expected to agree to a new in-game protocol forbidding any players to return to a game if they demonstrate "instability," according to ESPN's Adam Schefter. The rule could reportedly go into effect as soon as Week 5.

Minutes later, the NFL and NFLPA released a joint statement stating they had not made any definitive conclusion about medical errors or protocol violations concerning the Miami Dolphins quarterback, but have agreed that changes needed to be made to the league's concussion protocol.

Each organization's relevant committees have reportedly begun conversations around the term "gross motor instability," with changes anticipated in the coming days.

The NFL, the NFLPA and the Dolphins have been under fire ever since last Sunday, when Tagovailoa exited a game against the Buffalo Bills after visibly stumbling following a hit that caused his head to hit the turf hard. He was soon allowed to return, leading a Dolphins upset win and an NFLPA investigation.

Dolphins head coach Mike McDaniel said after the game that Tagovailoa had passed all concussion tests before making his return, but some still questioned allowing the quarterback to play four days later against the Cincinnati Bengals. Those fears were seemingly vindicated when Tagovailoa again hit his head against the turf and went into a clear fencing response, signifying a brain injury.

Tagovailoa was taken to a local hospital and discharged the same night, flying home to Miami with the team.

Tua Tagovailoa has no timetable to return after concussion

The next day, Tagovailoa released his first statement since the hit, thanking fans for their prayers and support but not saying much else about the situation.

Speaking with reporters, McDaniel indicated Tagovailoa was still experiencing headaches and had no timetable to return, a situation not uncommon with serious concussions. He was also again forced to defend his team's handling of the quarterback, insisting that all protocols had been followed after Tagovailoa's first hit.

McDaniel insisted he wouldn't have allowed Tagovailoa to play if he hadn't seemed like himself.

Neurologist who examined Tua Tagovailoa fired by NFLPA

The central issue with the Tagovailoa situation for the NFL has been the league was asking fans to ignore what their own eyes had seen at a time when the league has little benefit of the doubt for how it handles head injuries.

Some non-amateur neurologists were more hesitant to condemn the league, but the critics received a boost on Saturday when the NFLPA fired the independent neurologist who was involved in the decision to allow Tagovailoa to return to the Bills game. The union reportedly found "several mistakes" had been made in Tagovailoa's evaluation.

Now, the league and union are taking a stance even close to zero tolerance when it comes to potentially serious head injuries.