Police say the free agent wide receiver was in and out of consciousness and refused to leave the plane when asked.
According to a statement from the Miami-Dade Police Department, officers were called to the airport for a medical emergency after the flight crew expressed concern that Beckham was seriously ill.
The police statement said that the flight crew was concerned for Mr. Beckham, as they tried to wake him to put his seat belt on. The attendants called for police and fire rescue because they were afraid that Mr. Beckham's condition would get worse as the flight went on. The flight crew asked Mr. Beckham a number of times to leave the plane.
Beckham got off the plane when asked by officers, according to police. There was a video on social media that showed Beckham walking into the terminal.
Beckham wrote "never in my life have I experienced what just happened to me" in a series of posts on Sunday. I have seen it and called it a comedy.
American Airlines said in a statement that the plane returned to the gate because a customer failed to follow crew member instructions and refused to fastened their seatbelt. The flight left almost two hours late.
Beckham made other plans after being removed from the plane. He was not taken into custody.
Beckham, who has not played this season while recovering from a tornACL, was expected to meet with teams this week before a possible signing.
The Dallas Cowboys are thought to be the front-runner to sign Beckham, with the Kansas City Chiefs, Buffalo Bills, and San Francisco 49ers also in the running.