The Miami Heat and the Boston Celtics played “with a heavy heart” on Wednesday after seeing the US Capitol stormed by hundreds of supporters of outgoing president Donald Trump.
The riot came a day after prosecutors declined to bring charges against the police officer who shot Jacob Blake.
The incident in August caused the NBA to postpone games in protest.
A joint statement by Boston and Miami players read: “2021 is a new year, but some things have not changed.”
It went on: “We play tonight’s game with a heavy heart after yesterday’s decision in Kenosha, and knowing that protesters in our nation’s capital are treated differently by political leaders depending on what side of certain issues they are on.
“The drastic difference between the way protesters this past spring and summer were treated and the encouragement given to today’s protesters who acted illegally just shows how much more work we have to do.”
Trump had urged demonstrators to march on the Capitol in a bid to overturn the election result and the ensuing riot left four people dead.
Many spoke at Wednesday’s NBA games about the contrast between the suppression of Black Lives Matter protests last year and the reaction of authorities in Washington DC on Wednesday.
Virtually all Boston and Miami players knelt as the national anthem was played before the Celtics’ 107-105 win and said they would play to try “to bring joy into people’s lives”.
The US Congress has certified Joe Biden’s victory in the presidential election, hours after Trump supporters stormed the building in an attack that saw four people die.
Lawmakers resumed the session after police managed to remove the mob, which had been encouraged by President Trump in a bid to overturn his defeat.
The certification clears the way for Mr Biden to be sworn in on 20 January.
In response, Mr Trump pledged an “orderly transition” of power.