Seattle Seahawks running back Marshawn Lynch spent the few minutes he was on the podium at Tuesday's Super Bowl media day saying, over and over again, "I'm just here so I won't get fined."

Unfortunately, for Lynch, showing up wasn't the only criteria. Sources tell ESPN that, after the Super Bowl, the league will review whether the hat Lynch wore during the event, which bears his "Beast Mode" logo, was permissible. If the NFL rules that Lynch used media day to promote a brand that was not approved by the league, he could face a significant fine. NFL spokesman Brian McCarthy declined to comment.

At Wednesday's media availability, Lynch wore another hat with the Beast Mode logo, with different colors. His Wednesday appearance lasted about five minutes. He responded to reporters' inquiries by repeatedly saying, "You know why I'm here," before concluding the session with "Thank you, I appreciate it," and leaving.

The NFL makes clear to players that they cannot wear brands that conflict with league partners on the field during games and during postgame interviews. That is extended to Super Bowl media day, where a record number of cameras are on the players.

That's why the league fined Chicago Bears linebacker Brian Urlacher $100,000 for wearing a Vitaminwater hat on his podium during Super Bowl XLI in 2007. The league had, and still has, an official drink deal with Pepsi, which also owns Gatorade.

Lynch's Beast Mode hat was selling on the clothing line's website and advertised as "the hat Marshawn wore during the 2015 SB Media Day." The hat, which costs $33, sold out and the site noted Wednesday morning that it was hoping to restock it as soon as possible. Lynch owns four trademarks to the phrase "Beast Mode" and has filed for three additional trademarks with the U.S. Patent and Trademark Office.

Sources say the NFL is considering whether Marshawn Lynch's "Beast Mode" hat constitutes a violation of league rules about approved sponsors. Christian Petersen/Getty Image

The league frowns on players using what is considered a league event to promote something that it has not approved. And despite Lynch's short time on the podium Tuesday and Wednesday, he certainly got a lot of free advertising from news clips and social media showing the hats.

Lynch's situation isn't exactly parallel to Urlacher's in that Lynch wasn't wearing a brand that competes with a league sponsor. The hat is made by New Era, which is the official hat of the NFL.

Seahawks quarterback Russell Wilson came to his teammate's defense Wednesday.

"I just think that sometimes we focus on things that don't matter and don't make any difference," Wilson said. "Marshawn is a great football player and a guy that puts his work in every day and is dedicated to the game of football and dedicated to his teammates. There are times I don't think he should be fined, especially to extent that people try to fine him. That's just my honest opinion.

"The guy loves the game. Sometimes people try to take away from people the way they are. I don't think he should be fined, personally."

Lynch is no stranger to fines. In November, he was fined $50,000 for not talking to the media and another $50,000 that was being withheld by the league from the 2013 season that was contingent upon his future cooperation with the press. Lynch was also fined $11,050 for grabbing his crotch after a touchdown in a late December game against the Arizona Cardinals. He was fined $20,000 for doing the same thing in the NFC Championship Game.

Online sportsbook Sportsbook.com had a prop bet on whether Lynch would get fined for media day. The odds of that happening were set at 8-to-1, but the sportsbook lowered odds significantly after bets came in heavy for Lynch to get docked.

ESPN Seahawks reporter Terry Blount contributed to this report.