The quarterback has claimed teams colluded to keep him out of the league this season, and his recent lawsuit suggests Trump helped foster this negative culture toward him.
In September, the president said NFL teams should fire players who take a knee during the national anthem, which Kaepernick had done since the start of last season.
Trump followed up his thoughts with a series of tweets discussing those who kneel during the national anthem and recently stated these players should be suspended.
Over 100 players took a knee in protest in Week 3 following the original comments, while several around the league continue to protest racial injustice with this act.
Kaepernick—who remains unemployed despite a quality individual season in 2016—planned to file a collusion lawsuit under the collective bargaining agreement, as first reported by Bleacher Report's Mike Freeman.
While proving such an act could be difficult, La Canfora noted the plan to discuss Trump's role in influencing teams, noting his relationship with New England Patriots owner Robert Kraft and Dallas Cowboys owner Jerry Jones.
Mark Geragos, Kaepernick's lawyer, also hinted at the president's influence in his official statement.
"Athletes should not be denied employment based on partisan political provocation by the Executive Branch of our government," Geragos said, via Ian Rapoport of NFL Network.
Kaepernick has not been brought in for any workouts this season despite several notable injuries around the league.