But that isn't something that should come as a surprise to fans given that Lynch hasn't stood for the anthem in 11 years, according to NBC Sports Bay Area's Fallon Smith.
After Saturday's game, Raiders head coach Jack Del Rio told reporters that he didn't think Lynch's sitting would be a distraction, according to the Arizona Republic, and said the gesture was "a non-issue for me". But I respect him as a man and he can do his thing.
"It's a non-issue for me", Del Rio was quoted as saying.
Lynch is attempting a comeback into the National Football League after retiring at the end of the 2015 season.
Lynch has voiced his support for quarterback Colin Kaepernick's decision to kneel during the anthem to protest police brutality against people of color.
Without hearing from Lynch, it's impossible to say for sure what he intended to say by sitting out the anthem, or what he meant when he explained himself to his coach afterward.
Lynch, who last spoke to the media in June, did not speak to reporters after the game.
Last year, during a televised interview on Conan O'Brien's late night talk show, Lynch lent his support to fellow sportsman Colin Kaepernick who knelt while the USA national anthem was played to protest police brutality and institutional racism in general. But unlike those demonstrations, many consider what Lynch did on Saturday as not a protest.
"I just hope people open up their eyes to see that it's really a problem going on and something needs to be done for it to stop", Lynch told comedian Conan O'Brien in September 2016.
As The Washington Post's Des Bieler wrote, many believe Kaepernick's protests are the reason the quarterback, who led the 49ers to Super Bowl XLVII in 2013, remains unsigned. "If you're really not racist then you won't see what he's doing as a threat to America".