RENTON, Wash. — The Seattle Seahawks have been fined $100,000 for not properly following concussion protocol with quarterback Russell Wilson during a game in November.

The NFL and NFLPA announced their decision on Thursday following an investigation that lasted more than a month. Along with the financial penalty, Seattle’s coaching and medical staffs will be required to attend remedial training regarding the concussion protocol.

Seattle is the first team fined for such a violation. The investigation determined that Wilson was allowed back on the field before a required evaluation was performed on the sideline.

The Seahawks said Thursday that they accepted the results of the investigation and any missteps in violating the protocol were not intentional.

“I guess that’s what they decided to do. I thought everything was done in the right way,” Wilson said Thursday. “There was a lot of confusion. I didn’t really understand why I was coming out of the game anyway. I was completely clear. My jaw was a little messed up. Other than that; that’s what they decided.”

Wilson was hit in the chin by Arizona’s Karlos Dansby, who was flagged for roughing the passer. Referee Walt Anderson sent Wilson off the field. But Wilson was in Seattle’s injury tent for only a few moments and he missed just one play before returning to the field.

“In this case, through a series of communication breakdowns, the protocol not followed,” NFL spokesman Joe Lockhart said Thursday. “The player was allowed to return to the game without going through the protocol, a clear violation.

“The protocol was significantly strengthened over the postseason, but we’re always looking for ways to make it better.

“In this case, all the medical personnel, coaches and referees have been told going forward, when a referee removes a player, that player has to be received by medical personnel. It can’t be to a coach.”

THE NFL has told its officials not to use index cards or any other paper to aid in measurements. In Sunday night’s Cowboys-Raiders game, veteran referee Gene Steratore tried to slide what appeared to be an index card between the tip of the ball and the end of the chain while measuring for a first down. When the card didn’t slide through, Steratore signaled a first down for Dallas. He said he had decided it was a first down before the odd measurement.

NFL officiating chief Alberto Riveron on Thursday confirmed what Steratore said.

“Using a piece of paper, that’s very unusual,” Riveron said. “That is not the norm. Gene made the decision strictly on visual affirmation that the ball made the line to gain.

“I will advise them not to use it again. I have already done that.”

SAINTS: New Orleans placed Kenny Vaccaro on injured reserve, ending the starting safety’s season.

Vaccaro has been in and out of the lineup with groin injuries since a Week 9 victory over Tampa Bay on Nov. 5. He has made or assisted on 60 tackles this season, including a sack-and-a-half and seven tackles for losses. He also has three interceptions to go with seven passes defended and also has recovered a fumble.

Vaccaro has been with New Orleans since he was a first-round draft choice in 2013.

VIKINGS: Minnesota left tackle Riley Reiff’s sprained ankle has improved, and the team has listed him as questionable to play at Green Bay.

Reiff practiced on a limited basis Thursday after missing the previous game.

PANTHERS: The NFL made it clear Thursday it isn’t forcing Panthers owner Jerry Richardson to sell the team while he is under investigation for sexual and racial misconduct in the workplace.

NFL spokesman Joe Lockhart said during a conference call that “there was no pressure from the league on Mr. Richardson” to sell his team.

Lockhart said Richardson “came to the conclusion over that weekend that putting his team up for sale was what he wanted to do. We found out about it shortly before the announcement came out.”

The NFL plans to hire outside counsel to conduct the Richardson investigation, but a final decision has not been made on which firm.

TITANS: Cornerback LeShaun Sims will miss Sunday’s game against the Rams with a hamstring injury that likely will sideline him the remainder of the season.