During the 2005 college football season, Sewell redshirted as a true freshman. Entering the 2006 season, he was third on the depth chart behind redshirt senior Christian Olsen and redshirt junior Kevin McCabe. When Olsen struggled during the season opener, a loss to Pittsburgh, both McCabe and Sewell received playing time. Sewell did not play in the following game, when McCabe relieved Olsen and led the Cavaliers to a victory over Wyoming. McCabe started in the next game, against Western Michigan, but was benched in favor of Sewell after halftime. Sewell started Virginia's remaining nine games in the 2006 season, beginning with a game at Georgia Tech. The Cavaliers posted a record of 4-5 in those games to finish the season with a 5-7 record. Despite generally positive opinions of Sewell's progress by fans and the media, Virginia finished near the bottom in most offensive categories in NCAA Division I-A.