McCown, 35, was Tampa Bay's starter during last year's 2-14 season. He missed five games with a thumb injury, but his starting job was given back to him even though Mike Glennon played reasonably well in his absence.
McCown completed 184 of 327 passes (56.3 percent) for 2,206 yards with 11 touchdowns and 14 interceptions for a 70.5 passer rating. The Bucs won only one game with McCown as their starter. McCown previously said he would be fine with staying with the Bucs as a mentor to a rookie. He was scheduled to earn $5 million in 2015.
Glennon had the same number of wins as McCown, and it's not likely the Bucs will look to him to be more than a backup.
The Bucs have the first pick in the draft, and all indications are they will use it on a quarterback, likely Jameis Winston or Marcus Mariota.