The Sun-Sentinel reported that wide receivers Kenny Stills and Albert Wilson sat on the bench while other players lined up for the playing of the Star-Spangled Banner before kickoff against the Tampa Bay Buccaneers.
Quinn stood and raised his right fist, as he did during the anthem last season with the Rams.
There were no apparent demonstrations by the Buccaneers.
In July, the NFL chose to suspend its new anthem policy which required all players on the field to stand for the national anthem. The Dolphins issued a statement before training camp saying all options regarding the team's policy remain open.
"As a black man in this world, I've got an obligation to raise awareness", Quinn said.
The only teammate to do the same was cornerback De'Vante Bausby.
"What NFL owners did today was thwart the players' constitutional rights to express themselves and use our platform to draw attention to social injustices like racial inequality in our country", Jenkins said in a statement in May.
"My brother @kstills continued his protest of systemic oppression tonight by taking a knee", the tweet said. "You know what I mean?"
After confusion, the National Football League chose to take its new policy back to the drawing board and consult with the players association.
However, that policy, announced in May, was put on hold last month when the NFL and the NFL Players Association agreed to suspend enforcement of the new rules.
"Meanwhile, there has been no change in the NFL's policy regarding the national anthem".
The league noted that while players won't be disciplined, it expects all players on the field to stand during the presentation of the flag and the anthem.
The rule would have fined teams whose players protested during the anthem, but allowed the teams the choice to wait in the locker room or tunnel while the anthem was performed.
"We remain committed to working with the players to identify solutions and to continue making progress on important social issue affecting our communities".