The team announced Mettenberger's release on Monday. The sixth-round pick in 2014 was claimed by Pittsburgh via waivers in August but didn't play a regular-season snap for the team.
Joshua Dobbs was selected with the same number pick as Dak Prescott in 2016. The two shared similar successes in the SEC.
After being selected by the Tennessee Titans in the sixth round of the 2014 draft, Mettenberger started 10 games in 2014 and '15, going 0-10 in those starts. In 14 games overall those two seasons, he threw for 2,347 yards, 12 touchdowns and 14 interceptions.
He spent part of last offseason with the Chargers, who released him.