"When you're 3-13 and 1-14, that just doesn't cut it," Kotite said. "If you take emotion out of this, and I did, it's clear that the head coach should step down."
He said his departure was by mutual agreement with Leon Hess, the team's owner, and Steve Gutman, its president.
Kotite gave a contradictory statement in announcing he was leaving.
"I was not fired, I am not quitting," he said, perhaps implying that as the team's general manager he could dismiss himself.
Running back Erric Pegram limped off the Pittsburgh Steelers' practice field with a calf muscle injury that ended his season.
There was no contact, and Pegram was at a loss to explain how his right calf either tore or was strained. He was put on injured reserve, and running back Terry Richardson was promoted from the practice squad.