Eric Reid, the Carolina Panthers safety known for protesting during the national anthem, has long been open about the contempt he holds for Philadelphia Eagles defensive back Malcolm Jenkins. That animosity spilled over into an on-field confrontation Sunday before the teams had even played a down.

After the coin toss, Reid approached Jenkins near midfield and the two appeared to exchange heated words, with Reid eventually being restrained by his teammate Torrey Smith. After the game, a 21-17 comeback victory for the Panthers, Reid said of Jenkins, “He’s a sellout.”

Reid, who joined Colin Kaepernick in protesting police brutality and societal inequality for people of color in 2016 by kneeling during the national anthem before games, has been at odds with Jenkins since November 2017. That is when Reid left a so-called Players’ Coalition led by Jenkins and Anquan Boldin because he thought Jenkins was leading the players down the wrong path, accepting an offer by the N.F.L. to make charitable donations in exchange for the players’ ending their on-field protests.

Jenkins, who had previously raised his fist during the national anthem, ended his protest after the coalition secured nearly $90 million in funding for its causes. He briefly protested again during this year’s preseason but has not done so during the regular season.