Players on Duke wore black t-shirts that read "Equality" during warm-ups before their exhibition game against last year's Division-II champion Northwest Missouri State.
The entire team wore the shirts for warm-ups and while sitting on the bench during the game.
Duke coach Mike Krzyzewski has spoken out about political issues in the past, calling North Carolina's bathroom bill "embarrassing" back in 2016.
The Blue Devils are the Preseason No. 1 in the USA Today Coaches Poll.