76ers, Celtics Kneel During National Anthem Before Preseason Game

Members of the Philadelphia 76ers and Boston Celtics knelt during the national anthem prior to Tuesday's preseason game.

Many NBA players began kneeling during the anthem when action resumed at Walt Disney World Resort over the summer.

Prior to the restart, protests against police brutality and systemic racism grew across the country. Shining a spotlight on social justice issues became a focus for those players who had traveled to Orlando, Florida.

With the regular season set to tip off Dec. 22, Sixers head coach Doc Rivers told reporters during the team's media day that he didn't want his players to lose sight of larger aims beyond basketball.

"We have to keep our eye on the ball; we have to stay engaged," Rivers said. "The players have to stay engaged. ... As I told a couple of our players, we can't be Milli Vanilli. We can't be one-hit wonders that aren't true. We have to stay with it."