After Tua Tagovailoa's concussion, protocols enter spotlight: What happened in Sunday's NFL games

Isaiah McKenzie caught a slant over the middle with Baltimore Ravens defensive back Brandon Stephens running after him. As Stephens dragged the Buffalo Bills wide receiver to the ground, safety Chuck Clark lowered his shoulder, which collided with McKenzie's helmet.

Sandwiched between the two defenders, McKenzie did not immediately pop up following the 3rd-and-7 conversion. He was clearly shaken up. McKenzie rose and jogged off the field without assistance minutes later, but the Bills ruled him out with a concussion for the rest of their 23-20 victory.

What McKenzie and Buffalo experienced Sunday is just one example of players and teams navigating the five-stage protocols agreed upon by the league and NFL Players' Association. The process has faced heightened scrutiny since Miami Dolphins quarterback Tua Tagovailoa suffered separate injuries in back-to-back games – four days apart. Since Thursday's concussion incident, the NFLPA fired the unaffiliated neurotrauma consultant who was involved in treating Tagovailoa on Sept. 25 for his initial head injury. The NFL and NFLPA have announced they will modify the concussion protocol.

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But the way the league identifies and treats head injuries remains inconsistent. On "Sunday Night Football," Tampa Bay Buccaneers tight end Cameron Brate collided with teammate Chris Godwin and jogged off the field (not before a 12-man penalty was called). He missed two plays and returned. At halftime, the Buccaneers ruled him out with a concussion.

“We have one very simple goal here. We want to diagnose and recognize every single concussion that occurs on our field," NFL chief medical officer Dr. Allen Sills said Sunday. "We want to provide best-in-class care in the world for our athletes.”

NBC analyst and Hall of Fame coach Tony Dungy, who watched what happened to Brate from the sidelines, said it was a result of a “broken system.”

“Obvious he had his bell rung,” Dungy wrote on Twitter. “There’s a league-appointed spotter in the press box who should stop play (and) alert the referee. Brate shouldn’t have been allowed to return until after an evaluation. Why didn’t that happen???”

Giants backup quarterback Tyrod Taylor is in concussion protocol after he sustained a massive hit near the sidelines against the Chicago Bears. Giants safety Julian Love also left with a concussion but tweeted: "I'm all good. Will be back soon."

Meanwhile, Indianapolis Colts linebacker Shaq Leonard will miss "Thursday Night Football" with a concussion. Leonard made his season debut Sunday. Teammate Tyquan Lewis also suffered a concussion and will be out Thursday.

"These decisions were already made that they will be out, even if there was some miraculous (recovery)," Reich told reporters Monday when asked if the protocol played a factor in their status.

The Denver Broncos had two players evaluated for concussion: safety PJ Locke and linebacker Aaron Patrick. In the same game, the Las Vegas Raiders saw linebacker Denzel Perryman go down and coach Josh McDaniels confirmed he was in the protocol Monday.

Quarterback Bailey Zappe made his NFL debut under center for the New England Patriots, but only after Brian Hoyer left and was evaluated for a head injury. Green Bay Packers safety Adrian Amos made a tackle for loss in the first quarter of that game and was ruled out after being evaluated for a concussion.

Houston Texans linebacker Blake Cashman entered concussion protocol after he made a tackle on a punt. The Pittsburgh Steelers placed safety Terrell Edmunds in the concussion protocol as well.

This article originally appeared on USA TODAY: Tua Tagovailoa's concussion, protocols collide: What followed for NFL