"Got some awful news from my father a contractor deny giving him a job on doing a house because of my peaceful protest," Spence wrote on Twitter, adding a hashtag for the phrase "shaking my head."
On Wednesday, the 25-year-old Florida native told the Detroit Free Press his decision to protest was not aimed toward the American flag, but rather the concept of "right and wrong."
"Us guys, we'll talk about it here in the locker room and if we feel strongly enough about it, but it'll probably be something that continues just cause of what's going on in our country, the injustice and everything like that," he said. "And like we always say, it's no disrespect to the American flag. Guys just trying to bring it about. It's about right and wrong, like I always say, and what's right is right and what's wrong is wrong. It's no offense to nobody, no disrespect, just like I always tell people, love one another and we'll be all right."
Former San Francisco 49ers quarterback Colin Kaepernick started the movement of kneeling while the national anthem played during the 2016 preseason. He explained to Steve Wyche of NFL.com last August the decision was to protest social injustice.
"I am not going to stand up to show pride in a flag for a country that oppresses black people and people of color," he said. "To me, this is bigger than football and it would be selfish on my part to look the other way. There are bodies in the street and people getting paid leave and getting away with murder."
Debate about the players' protests was reignited last week when United States President Donald Trump suggested NFL owners should fire any player who doesn't stand for the song.
A Remington Research Group poll released Monday noted 51 percent of respondents said they were watching less football this year and 69 percent of those people said the reason was "players using the NFL as a stage for their political views."
Spence and the Lions return to action Sunday for a road game against the Minnesota Vikings at U.S. Bank Stadium in Minneapolis. It's unclear whether the defensive tackle will continue his protest.