Robert Griffin III turned in one of the most-impressive quarterback debuts in NFL history Sunday, but his pregame attire is what caught the attention of the league, according to ESPN.com.
While warming up for the Washington Redskins' season opener against the New Orleans Saints, Griffin donned a shirt inscribed with the word "Heart" running down the left side, the "H" concealing the logo of official NFL apparel sponsor Nike. Griffin has a lucrative endorsement deal with adidas.
Players are not allowed to cover up Nike's logo, but can wear brands of sponsors that have deals with the NFL, according to the report.
NFL spokesman Brian McCarthy told ESPN.com that league officials plan on talking to Griffin.
"It won't happen again," McCarthy said.
Griffin made an immediate impact in his first professional game, throwing for 320 yards and two touchdowns in a 40-32 win.