(TheBlaze/AP) -- Opening day in the NFL saw Kansas City cornerback Marcus Peters raise a black-gloved fist during the national anthem, a protest amplified later Sunday when four Miami Dolphins kneeled on the sideline with hands on their hearts as "The Star Spangled Banner" played in Seattle.
From left, Miami Dolphins' Jelani Jenkins, Arian Foster, Michael Thomas, and Kenny Stills, kneel during the singing of the national anthem before an NFL football game against the Seattle Seahawks, Sunday, Sept. 11, 2016, in Seattle. (AP Photo/Stephen Brashear)
The protests were inspired by San Francisco backup quarterback Colin Kaepernick , the first NFL player who chose to sit and take a knee during the anthem in preseason games to call attention to what he termed the oppression of blacks and other minorities.
Peters' gesture was the only one visible throughout the early games Sunday, as the anthems took on more significance because of the 15th anniversary of Sept. 11 attacks.
"I come from a majority black community from Oakland, California ... so the struggle, I seen it," Peters said after the Chiefs beat San Diego 33-27 in overtime. "I still have some family in the struggle. All I'm saying is we want to educate those, the youth that's coming up."
Marcus Peters of the Chiefs, raising his fist during anthem. Dissent - especially in this NFL climate, - is brave. https://t.co/VaGNS5pD45— Dave Zirin (@Dave Zirin)1473614371.0
However, the new style of protest was seen again during Sunday Night Football.
In New England, two more players raised their fists.
The four Miami players - Arian Foster, Michael Thomas, Jelani Jenkins and Kenny Stills - registered their protest shortly before kickoff. All four stood at the conclusion of the anthem.
Several teams, including the Chiefs and Seahawks, saw their players link arms during the anthem. Peters, the 2015 defensive rookie of the year, was the last person in the Chiefs line and had his arm free to raise it.
"He spoke up about something he felt he needed to speak up about," Peters said last week. "I salute him for that."
Broncos linebacker Brandon Marshall , a teammate of Kaepernick's in college at Nevada, took a knee during the anthem on Thursday night.
NFL commissioner Roger Goodell weighed in on Kaepernick's protest last week as well, saying, "I don't necessarily agree with what he's doing."
Taped messages from Presidents Barack Obama and George W. Bush were played at each stadium. Bush attended the Giants-Cowboys match in Arlington, Texas, while Vice President Joe Biden was in Philadelphia for Browns-Eagles.
Peters' gesture was also a tribute of sorts to U.S. sprinters Tommie Smith and John Carlos, who won the gold and bronze medals, respectively, in the 200-meter race at the 1968 Olympics. Both then appeared on the medal stands with raised, black-gloved fists throughout the U.S. national anthem in what they called a "human rights salute."
And in the night game, New England's Martellus Bennett and Devin McCourty both held up their right arms. Teammate Danny Amendola was seen clutching the American flag unfurled on the field in Arizona.
The International Olympic Committee ordered Smith and Carlos expelled from the games because of the protest.