Donald Trump's longstanding commentary on the NFL and its players protesting racial injustice has made headlines since he decided to let his unfiltered thoughts known on Twitter in recent months. One name that continues to surface on his timeline is Colin Kaepernick.

The former San Francisco 49er quarterback has remained vocal on fighting for economic and social justice for communities of color and remains a free agent in the league since doing so. While Kaepernick worked alongside national organizations geared toward his cause, Trump continued to speak out against fellow athletes that are standing for justice. Recently, Trump seemingly supported the NFL's pending policy that'll penalize players who protest by kneeling during the national anthem.

Now, Kaepernick and his legal team want to get to the root of the NFL's decision, beginning with a subpoena against Trump and his administration, Yahoo! Sports reports. The legal group wants to analyze the White House's "political involvement" in the NFL, specifically concerning the period around Kaepernick's free agency.

During a September 2017 rally, Trump didn't mince words when he offered what NFL owners should do to players that protest on the field.  “Wouldn’t you love to see one of these NFL owners, when somebody disrespects our flag, to say, ‘Get that son of a bi**h off the field right now, out, he’s fired,” he said.

Details on the potential legal proceeding are still forthcoming.