Colin Kaepernick’s legal team is expected to seek federal subpoenas to compel testimony from American President Donald Trump, Vice President Mike Pence, and other government officials in his ongoing legal battle with the NFL, according to a report from Yahoo Sports.

The goal of the subpoenas, according to the report, is to find out the involvement that Trump, Pence, and other officials had with the NFL concerning player protests and Kaepernick’s free agency.

Kaepernick was the first player to kneel during the national anthem to protest racial injustice and police brutality and has not been signed by an NFL team since opting out of his contract with the San Francisco 49ers in March 2017. The 30-year-old is suing the league for collusion in not signing him to a contract.

The Yahoo Sports report comes after the Wall Street Journal reported last month that several NFL owners consulted President Trump on how to handle player protests during the national anthem.

Trump has been outspoken in his opposition of anthem protests, suggesting owners should pull players who kneel from the game.