Meyers Leonard stood for the national anthem before the Miami Heat played the Denver Nuggets.
"I think I can be a beacon of light ... not only for my voice or platform and action, but in everything I'm doing," Leonard, who is white, told Marc J. Spears of ESPN's The Undefeated after the game. "I certainly support Black Lives Matter. ... I am very aware of what is going on. But I can be both. My patriotism runs deep."
Jonathan Isaac, Gregg Popovich and Becky Hammon have also stood for the anthem.
Leonard cited his respect for the U.S. military. His brother Bailey Leonard served two tours in Afghanistan with the Marines.
"I haven't slept. I'm a zombie right now. It's been difficult because the truth of the matter is I have a loving heart, very compassionate and I'm very aware of what is happening in America today and what has been going on for many years," Leonard told Spears.
"I [was] aware some of the backlash that could happen. I understand. However, I believe in my heart that I did the right thing," Leonard told Spears. "Our world right now is black and white. There is a line in the sand, and it says if I don't kneel, then I'm not with Black Lives Matter. That is not true."
Leonard also spoke to his brother and Navy SEALs.
"I understand that [kneeling during the anthem] is not about the flag and the military, but to me, it is. Based upon real-life experiences and real raw emotion that I've had in my life, that is what that means to me," said Leonard, who was wearing military-style boots, backpack and mask.
He added: "And I'm hopeful that people that don't know me can either learn or ask. I did in my heart what was right to me."