He "should've" and/or "could've been the Colin Kaepernick
https://www.courant.com/sports/baske...tou-story.html
Then Abdul-Rauf refused to stand for the national anthem. He had been doing so for the entire season, for months, but it wasn't until mid-March when reporters noticed.
By the 1995-96 season, he had hit a good groove. He was the team's scoring leader and tallied 51 points in a single game against the Utah Jazz. He had also begun to sit out the national anthem for what he would later say were religious and political reasons. He would either stretch on the sidelines or wait in the locker room until the anthem was over.
At the end of the season, the Nuggets traded him - their highest-scoring player - to the Sacramento Kings. There, coaches put him on the court less and less. It was a process to weed him out, he told the Undefeated. When his contract ended in 1998, no NBA team would take him.