Johnson was released by the Raiders on Thursday, Field Yates of ESPN reports.
Johnson was always viewed as a long shot to make the Raiders' final roster when he was signed back in March, as the team is fairly secure at the quarterback position with Derek Carr, EJ Manuel and Connor Cook all still on the roster. Johnson has floated around the league since being drafted back in 2008, and he could potentially still find a backup job at some point down the line if a team is in need of depth at the position.