The 32-year-old veteran guard had his reasons for doing so.
"I don't feel like the flag represents what it's supposed to at this point," Smith said following Friday's shootaround, according to Cleveland.com's Joe Vardon. "We obviously didn't discuss what we were going to do as a team, and I definitely, I don't feel, it's not an easy situation for me with the national anthem.
"Especially coming from where I come from, it's just not. I don't feel like it's represented the right way, obviously it's a tough conversation for everybody, and it still needs to be, I wouldn't say talked about, because there's been a lot of conversations about it, it's time to start doing. What efforts are we going to put toward it?"
Smith has shared his feelings about the state of America and President Donald Trump in the past on social media, not shying away from letting his displeasure be known on a number of political and social matters currently at the forefront of people's minds.
He went on a Twitter rant back in August after people took to the streets in Boston to protest hate speech following the attacks and riots in Charlottesville involving white supremacists. Smith took shots at Trump - albeit without calling him out directly - and the irony of the president's "Make America Great Again" slogan while hate continues to seep across the country.
Despite his feelings about the flag, Smith did lock arms with his Cavaliers teammates during the anthem ahead of their preseason opener Wednesday.