Updated

Former teammate Alex Boone isn’t taking any more hits for embattled San Francisco quarterback Colin Kaepernick.

The offensive guard suited up for five seasons alongside Kaepernick, blocking as defenders tried to get Kaepernick off his feet. Now, Kaepernick is voluntarily taking a seat, choosing to sit during the playing of The Star-Spangled Banner to protest perceived racial injustice. It may be a good thing that Boone, now with the Minnesota Vikings, is no longer wearing the same jersey as Kaepernick.

“We probably would have had a problem on the sideline,” Boone told ESPN.

Boone’s brother J.J. was a Marine and served in Iraq, making Boone one of several current or former NFL players, many with military connections, to speak out about Kaepernick following his second sitdown before a preseason game on Friday.

“You should have some f---ing respect for people who served, especially people that lost their life to protect our freedom," Boone said. “We're out here playing a game, making millions of dollars. People are losing their life, and you don't have the common courtesy to do that. That just drove me nuts.”

Carolina Panthers coach Ron Rivera is the son of an Army officer and lived on military bases most of his young life. His father, Eugenio Rivera, served two tours of duty in Vietnam.

“To me, it’s a very personal thing because of my dad, his military background, knowing that his family and my mom’s family served in the military,” Rivera told Black and Blue Review.

“My view is [the anthem] is about honoring the people that served and made the commitment to our country, some who even made the ultimate sacrifice. When I stand, that's what I'm standing for. I'm standing for the people that came before my father and the people that came after him.”

Burgess Owens, a safety who played ten seasons in the NFL, said Kaepernick is “ignorant” about American history, and even black history.

“What this young man doesn’t understand is the very first martyr for freedom in our country was a black man, he doesn’t understand the Tuskegee airmen, who had hundreds of battles over the skies of Germany so he can sit and be ignorant as he wants to be today,” Owens told “Fox & Friends.”

“It’s not a racial crisis we’re at. At this point it’s an ideology crisis.”

Ex-wide receiver Randal Hill, who’s also running for a Florida congressional seat as a Democrat, told “Fox & Friends” that Kaepernick’s display would have never been tolerated on some of the teams he played on during the 1990s.

“[Coach] Buddy Ryan would always have us stand on the sideline at attention and he would film the playing of the national anthem, and if you moved at all, that was a $1,500 fine,” Hill said.

A popular meme circulating on the Internet Monday compared the careers of Kaepernick with former 49ers running back Glen Coffee. Both men were born in 1987, played for the 49ers and were drafted in the third round. But, unlike Kaepernick, Coffee quickly left football and pursued a life of military service.

Boone used an even starker comparison to make his point.

“You see all these pictures of these veterans that have no legs, and they're standing up in a wheelchair,” he said. “I had a brother that served, and he lost friends. I know how much it means to him. It's shameful.”

Philadelphia Eagles rookie linebacker Myke Tavarres told ESPN on Monday he would join Kaepernick in protesting by sitting down during the anthem.