As an offensive tackle for the Chargers and the Raiders, Ron Mix shielded quarterbacks from attack.

Although he retired from the NFL in 1972, Mix is still on the job.

“I kind of admire his courage,” Mix, a Pro Football Hall of Fame inductee, said of 49ers quarterback Colin Kaepernick. “He’s speaking out against obvious injustices that are taking place.”

Before a preseason game last Friday, Kaepernick sat during the playing of “The Star-Spangled Banner.” Afterward, he explained that he could not honor the national anthem or “show pride in a flag of a country that oppresses black people and people of color.”

His actions drew praise and condemnation — and added interest to tonight’s otherwise inconsequential game at Qualcomm Stadium. When the 49ers and Chargers meet for a final preseason contest — which happens to coincide with the home team’s 28th annual “Salute to the Military,” a fireworks-and-flags extravaganza — Kaepernick intends to continue his protest. How will local fans respond?

This is the talk of the virtual town, as Twitter, Facebook and other social media outlets have been blitzed with comments pro (#VeteransFor Kaepernick) and con (#KaepernickSucks). The protest comes in the wake of the Black Lives Matter movement, in an era when arguments over police, the criminal justice system and race often devolve into overheated and under-considered screeds.

Some of the most thoughtful insights into the Kaepernick affair, though, come from people who wore the uniform.

The NFL uniform.

“He has the right to protest, and everybody else has the right to protest his protest,” said Miles McPherson, 56, pastor of The Rock Church and a former defensive back with the Chargers (1982-1985). “All of that doesn’t get us anywhere.

“You have to ask, Is there an issue? The answer is yes. So the question is, What can we do to solve this?”

Chris Hairston, a Chargers offensive lineman, is determined to crush Kaepernick — on the field. Off the field, he’s a fan, applauding his opponent for raising crucial if uncomfortable issues.

“I think it’s important to put a spotlight on it,” Hairston said during Wednesday’s practice. “I like the conversation it started.”

As the nephew of an Army veteran of Operation Desert Storm, Hairston said the military fights for for “freedom and equality,” not a flag or a song.

Yet the flag and the national anthem stir powerful emotions, noted Saladin Martin, whose football career at San Diego State led to the NFL, where he played for the Jets (1980) and 49ers (1981).

“Some think the flag represents the military, and we are a military town,” said Martin, 60, who lives in Chula Vista. “So you are messing with the Army, the Navy, the Marines. You are going to get a bad reception here.

“This is probably the worst, the last town he would want to come to.”

In fact, active-duty military members watching the Chargers’ workout Wednesday at Marine Corps Air Station Miramar were found on both sides of the issue.