The episode occurred midway through the third quarter of the Seahawks' 22-16 win over the Arizona Cardinals, when Wilson absorbed a hit to the chin from linebacker Karlos Dansby. Wilson did not show any obvious signs of a concussion, but referee Walt Anderson invoked his right to send Wilson off the field for a test.
The NFL concussion policy states that a player believed to have concussion symptoms cannot return to "practice or play" unless a team physician and an independent neurological consultant clear him. Teams can be fined if the league finds they did not follow protocol designed to ensure medical clearance before any player returns to the field.
This season, the league added blue sideline tents to allow the initial test to be administered in private.
With backup Austin Davis in the game, NBC's broadcast showed Wilson running to the sideline and then sitting down in the area where the tent would be pulled over him. But Wilson got back up before medical officials had a chance to join him and then replaced Davis after one play.
Wilson was on the field for two more plays before the Seahawks punted. During the change of possession, Wilson again entered the tent and remained there for a longer period of time. He was on the field when the Seahawks regained possession.
"A thorough review is underway," the NFL said in its statement. "According to the policy jointly developed by the NFL and NFLPA, if the Concussion Protocol is not properly followed the club is subject to discipline."
After the game, Wilson said he wasn't concussed on the hit and felt "completely clear."
"I was just trying to move my jaw. I was like, 'Ah, man, it's stuck,'" Wilson said. "I think I was kinda like laying down on the ground for a second just trying to get my jaw, and I think Walt thought maybe I was injured or something like that. I told him I was good, I was good, and he said, 'Come off the field.'
"I think Walt did a great job first of all. He made the smartest decision. I was fine, though, 100 percent fine. And then they finally went over through the whole concussion stuff and all that. We went through every question you could imagine, and I answered even some more for them just so they knew I was good, and then went back in there."
The NFL investigates all credible reports of policy violations. Teams can be fined up to $150,000 for a first offense of violating the concussion protocol, according to a policy enacted jointly with the NFL Players Association in 2016. Team employees or medical team members involved would also be required to attend remedial education.