Mapu was a solid starter before leaving on missions. In shape, he's better than either guy that started at the end last year by a long shot. For point of reference consider that he and Harrell were recruited the same year. Mapu got on the field sooner and became a starter in front of Harrell. As Sophomores, Mapu had 26 tackles and appeared in every game. Harrell had 10 in 8 games.
Bolden has improved and still has potential.
Depth at DT is the biggest question mark for the upcoming season.
Last year it was QB. Ainge answered and if he'd stayed healthy the Vols would have won 10+ and possibly played in a BCS game.
My prediction for this year is that if the Vols can find two solid backups at DT and at least two good WR's they'll win 10+, the east, and play in a BCS game.
If they solve these two problems, they could be dominant on both sides of the ball to include a better running game than alot people expect.