Can Patrick Mahomes Play AFC Championship? Here's The NFL Concussion Rules

Kansas City Chiefs quarterback Patrick Mahomes was injured during the AFC Divisional game on Sunday against the Cleveland Browns, and he didn't return because of a concussion. The Chiefs eventually won the game and now advance to play the AFC title game on Sunday against the Buffalo Bills, but there's a protocol Mahomes must follow in order to play the game.

The NFL has a five-phase rule regarding players who suffer a concussion, which includes going through four phases of a team doctor's evaluation, and then the player getting another evaluation from a league-approved Independent Neurological Consultant.

Here are the league's protocols (verbatim from NFL.com):

Phase 1
Symptom Limited Activity
The player is prescribed rest, limited or, if necessary, avoiding activities (both physical and cognitive) which increase or aggravate symptoms. Under athletic training staff supervision, limited stretching and balance training can be introduced, progressing to light aerobic exercise, all as tolerated.

Phase 2
Aerobic Exercise
Under direct oversight of the team's medical staff, the player should begin graduated cardiovascular exercise and may also engage in dynamic stretching and balance training. Neurocognitive and balance testing can be administered after after completion of Phase Two and the results can be interpreted as back to baseline.

Phase 3
Football Specific Exercise
The player continues with graduated cardiovascular exercises that are increased and may mimic sport-specific activities, and supervised strength training is introduced. The player is allowed to practice with the team in sport-specific exercise for 30 minutes or less with ongoing and careful monitoring.

Phase 4
Club-Based Non-Contact Training Drills
The player continues cardiovascular, strength and balance training, team-based sport-specific exercise, and participates in non-contact football activities (e.g. throwing, catching, running, and other position-specific activities).

Phase 5
Full Football Activity/Clearance
Upon clearance by the team physician for full football activity involving contact, the player must be examined by the Independent Neurological Consultant (INC) assigned to his club. If the INC concurs with the team physician that the player's concussion has resolved, he may participate in the club's next practice or game.

"Until cleared by this independent physician, a player may not return to contact practice or play in an NFL game," it read on NFL.com.

Patrick Mahomes
Quarterback Patrick Mahomes #15 of the Kansas City Chiefs is assisted off the field after an injury from a sack that would remove Mahomes in the third quarter of the AFC Divisional Playoff game against the Cleveland Browns at Arrowhead Stadium on January 17, 2021 in Kansas City, Missouri. Photo by Jamie Squire/Getty Images

Mahomes was hit by Cleveland linebacker Mack Wilson while running the ball during an option play during the third quarter, and Mahomes was slow to get up.

When team officials brought Mahomes to his feet, the quarterback was wobbly, and needed a little assistance to get to the sideline. He was later ruled out of the game because of a concussion and he never returned.

Chad Henne was brought in to replace Mahomes, and he guided the Chiefs downfield for a field goal to give Kansas City a 22-10 lead with 4:28 to play in the third quarter.

Cleveland scored a touchdown to make the score 22-17, and they needed either a stop, a turnover or a Kansas City field goal to have a chance at a dramatic comeback. Things looked good when Cleveland sacked Henne to set up a 3rd-and-14 at their own 35-yard line.

On the next play, Henne scrambled 13 yards to set up a 4th-and-1. Henne called a pass play, and he connected with Tyreek Hill for 5 yards and a first down, and Henne just kneeled on the ball to end the game from that point.

Mahomes was the NFL MVP for the 2018 season, and he led the Chiefs to a Super Bowl victory following the 2019 season. Mahomes was the Super Bowl LIV MVP, and the Chiefs were favored to win the Super Bowl again with Mahomes at the helm.

His status this week is unknown for now, though.