Tony Mendez, a veteran cue cards holder for David Letterman on "The Late Show," assaulted 15-time Emmy nominee staff writer Bill Scheft, and got himself fired in the process, Deadline reported on Sunday.

Mendez, 69, has been with Letterman for over 20 years, but recently got into a verbal argument with Scheft and Letterman over cue card changes. Overnight, the bad blood increased and Mendez stewed over other perceived personal insults from Scheft. The next day at work on Oct. 9, Mendez pushed Scheft up against a wall by his shirt.

Mendez was bounced from the Ed Sullivan Theater, and was notified of his termination on Monday. Stephen Colbert is expected to host the show starting next year when Letterman retires. Mendez will still be paid and receive benefits until Letterman leaves.

"I know I shouldn't have put my hands on him," Mendez told The New York Post. "But this has been coming for a long time."

Mendez said Scheft often stepped on his toes at work and told him what to do. Scheft would also micromanage when Mendez was making the cue cards, telling him to "put that on top" if he got a particular idea. He even said that he thinks Scheft was trying to put a wedge between him and the iconic late night host so Letterman would think poorly of Mendez.

"Bill was always undermining me - making himself out as Dave's No. 1," Mendez said. "Trying to pretend that I wasn't even in the room . . . little passive-aggressive things."

Scheft stayed home from work on Friday and has been telling his coworkers that he is suffering from post-traumatic stress disorder following the incident.

Cuban-born Mendez joined the show in 1993, following similar gigs with the cast of "Saturday Night Live" and "The Hollywood Palace."

The job was more about making sure the host's lines went smoothly, rather than just purely holding cards. Mendez said that sometimes Letterman would forget what order the jokes were in or a new one would be put into his lines.

He would often be in front of the camera, too, playing himself in recurring comedy skits or going back and forth with Letterman during his monologue.