(Reuters) - Philadelphia Eagles defensive players Malcolm Jenkins, Ron Brooks and Steven Means stood together with raised fists during the U.S. national anthem before their game against the Chicago Bears on Monday.
The trio joined the movement of athletes who are using the anthem as an attempt to draw attention to racial inequality.
Jenkins said last week he planned to join the protests, sparked by San Francisco 49ers quarterback Colin Kaepernick during the NFL's pre-season.
"Last week, we talked about doing some stuff, but we wanted to make sure that we didn't do anything to take away from the families that suffered from 9/11," Jenkins said in a radio interview on Friday, referring to games that coincided with the 15th anniversary of the Sept. 11 attacks.
"We didn't want to mess with that day, so we left last week alone. But moving forward, I'm sure there will be guys that will probably join in."
Kaepernick started the protest when he chose to stay seated, and then later opted to kneel, for the anthem. He said it was a gesture against injustice and police brutality.
Several players from the Los Angeles Rams, Miami Dolphins and Tennessee Titans protested during the anthem on Sunday, while Megan Rapinoe has also knelt during the anthem at the U.S. women's soccer team games.
Other NFL players have chosen to raise fists, recalling a similar demonstration by athletes Tommie Smith and John Carlos during their medal ceremony at the 1968 Olympic Games in Mexico City.
The protesting players have been seen as allies of the Black Lives Matter movement, which grew in response to a string of high-profile police killings of unarmed African-Americans across the country. About two-thirds of NFL players are black.
Other athletes and fans have spoken out against the protests, viewing them as disrespectful.
Writing by Jahmal Corner in Los Angeles; Editing by Greg Stutchbury