The NFL concussion protocol is a multi-stage system that governs how players are evaluated during games, removed from play, and gradually cleared to return to contact. Every player diagnosed with a concussion must complete a five-phase return-to-participation process and receive independent medical clearance before stepping back on the field. There is no fixed timeline for the process, because each concussion is different.
Who Is Watching During the Game
The protocol starts before anyone gets hurt. Every NFL game has several layers of medical personnel whose sole job is spotting potential head injuries in real time. The most visible are the Unaffiliated Neurotrauma Consultants (UNCs), independent physicians credentialed jointly by the NFL and the players’ union. They stand on the sidelines and monitor broadcast feeds, assisting team medical staff in identifying and diagnosing concussions. Because they have no affiliation with either team, their judgment isn’t influenced by competitive pressure.
Working alongside them are certified athletic trainer spotters, or AT spotters, who watch both the field and the TV broadcast from a booth. Their job is narrow but critical: spot plays where a player may have been hurt, especially head and neck injuries, and call down to the sideline to alert the team physician or head athletic trainer. AT spotters do not diagnose injuries or suggest treatment. They simply flag what they saw and describe how the injury happened.
Since 2015, AT spotters have had the authority to call a medical timeout and stop the game to pull a player off the field. They can only do this when two conditions are both met: the player shows obvious signs of disorientation or instability, and the player is clearly trying to stay in the game rather than seek medical attention. This rule exists because concussed players sometimes don’t recognize or won’t acknowledge their own symptoms.
What Happens on the Sideline
When a player is flagged for evaluation, the sideline assessment follows an internationally recognized framework. Medical staff look for a set of observable signs that warrant immediate removal from play: lying motionless on the field, falling without bracing, stumbling or showing poor coordination, appearing confused or giving a blank stare, having a seizure, or sustaining a facial injury after head trauma.
If the player is responsive and stable, the evaluation moves through several structured components. Doctors assess consciousness using a standardized scale that scores eye response, verbal response, and motor response. They check the cervical spine for pain, tenderness, and range of motion. They test coordination by having the player touch finger to nose and track objects with their eyes. And they ask a set of memory questions designed specifically for the sports setting: What venue are we at? Which half is it? Who scored last? Who did you play last week? Did your team win?
Certain findings, called “red flags,” require urgent medical attention and rule out any return to play. These include loss of consciousness, seizure, double vision, vomiting, severe or worsening headache, neck pain, weakness or tingling in multiple limbs, increasing agitation, and any visible skull deformity. A player showing any of these signs is done for the day, no exceptions.
The Five Phases of Return to Play
Once a concussion is diagnosed, the player enters a graduated return-to-participation protocol. The phases build on each other, and a player can only advance when the current phase produces no recurring symptoms.
- Phase 1: Rest and recovery. The player returns to normal daily activities like attending team meetings but does no physical exertion. Symptoms are monitored as they subside.
- Phase 2: Light aerobic activity. The player does low-intensity cardio to raise heart rate, such as 5 to 10 minutes on a stationary bike, walking, or light jogging. No weight lifting.
- Phase 3: Moderate activity. Heart rate increases further with moderate jogging, brief running, moderate stationary biking, and reduced-weight lifting. Head and body movement are reintroduced.
- Phase 4: Heavy non-contact activity. The player returns to sprinting, high-intensity biking, full weight-lifting routines, and sport-specific drills, but without any contact.
- Phase 5: Full football activity and clearance. The player participates in full-contact practice. If no symptoms return and cognitive testing is back to the player’s personal baseline, the team physician can clear the player for game action.
If symptoms reappear at any stage, the player drops back to the previous phase and starts that step again. This is why some players miss one game while others are sidelined for weeks. The protocol is symptom-driven, not calendar-driven.
How Final Clearance Works
Even after a team’s own doctors are satisfied that a player has recovered, there’s one more gate. The player must be examined and separately cleared by an Independent Neurological Consultant (INC), a physician jointly approved by the league and the players’ union who has no connection to any NFL club. The INC’s role is specifically to evaluate the player’s neurological health and confirm that the concussion has fully resolved.
Until the INC signs off, the player cannot participate in contact practice or play in a game. This two-physician requirement, one team doctor and one independent doctor, was designed to prevent situations where competitive pressure might rush a player back before he’s truly ready. The team physician makes the initial clearance decision, and the INC confirms it. Both must agree.
How the Protocol Has Evolved
The NFL first formalized its Game Day Concussion Diagnosis and Management Protocol in 2011, developed by the league’s Head, Neck and Spine Committee, a board that includes independent physicians, NFL-affiliated doctors, and advisors for the players’ union. The protocol is reviewed and updated every year to reflect current medical consensus on concussion identification and treatment.
Key additions over the years include the AT spotter system and their authority to stop play, the mandatory involvement of unaffiliated physicians on every sideline, and the expansion of “no-go” criteria that automatically disqualify a player from returning. After a high-profile 2022 incident involving Miami Dolphins quarterback Tua Tagovailoa, who returned to a game after stumbling and was later diagnosed with a concussion in a subsequent game, the league added ataxia (abnormal balance and coordination) as a mandatory removal criterion. These changes reflect an ongoing tension in the sport: protecting player health in an environment where athletes are motivated to stay on the field.
The protocol applies identically to every player regardless of position, experience, or the stakes of the game. A backup lineman in Week 3 goes through the same process as a starting quarterback in the Super Bowl.