Blough will enter the season as the No. 2 quarterback after it was determined that Tim Boyle (thumb) will undergo surgery for a broken right thumb, Tim Twentyman of the Lions' official site reports.
While it's not clear if Boyle will miss the entire season, Blough is set to serve as the backup for as long as the free-agent acquisition is sidelined. When forced into action for five games with Detroit in 2019, Blough managed 5.7 yards per pass attempt with a 54 percent completion rate.