Lynch was in uniform but did not play in the game, and photos show Lynch sitting on a cooler and holding a banana while the anthem played.
Lynch has spoken to the media just once since coming out retirement and joining the Raiders after a trade with the Seattle Seahawks last spring. That one time was during the offseason program.
Raiders coach Jack Del Rio said he was not aware of Lynch's plans to sit during the anthem, and Del Rio added that he spoke with Lynch after the game.
"(Lynch) said, 'This is something I've done for 11 years, it's not a form of anything other than me being myself.' I said, 'So, you understand how I feel. I very strongly believe in standing for the national anthem, but I'm going to respect you as a man. You do your thing and we'll do ours.' So that's a non-issue for me," Del Rio said, according to ESPN.
Raiders quarterback E.J. Manuel said Lynch's decision was "more of a personal thing" for him but said the team supports him.
Lynch was not in the NFL last season when San Francisco 49ers quarterback Colin Kaepernick kneeled during the national anthem in his protest against racism.