The defending national champs open practice Friday looking to replace 12 starters. A total of 15 players from last year’s team went to the NFL.

Here are three position battles to monitor:

1. Wide receiver

Top contenders: Kenny Bell, Kevin Norwood, Christion Jones, DeAndrew White, Amari Cooper

Marquis Maze and Darius Hanks are gone, having signed with NFL teams as undrafted free agents. But A.J. McCarron still has plenty of speedy targets available. Bell (6-foot-1, 180 pounds) appears locked in at one starting spot. The junior made four starts last season and finished with 17 catches for 255 yards and two scores. In the spring game, Bell had a game-high five catches for 86 yards and a touchdown. Norwood, another junior who caught seven balls last year, will try to fight off a group of freshmen and sophomores. At SEC media days, coach Nick Saban described Cooper as “a freshman who came in at mid-semester who showed some ability and talent to make some plays."

2. Cornerback

Top contenders: Deion Belue, John Fulton, Travell Dixon

Dee Milliner mans one corner spot after making three picks and breaking up nine passes last year. Blue and Dixon are juco transfers competing with Fulton for the other spot. Coming out of the spring, Dixon looked to have a slight edge. All three will get opportunities as the Crimson Tide revamps its defense in the wake of substantial NFL losses.

3. Outside linebacker

Top contenders: Xzavier Dickson, Jonathan Atchison

Dickson (6-foot-3, 262 pounds) was one of seven true freshmen to play last season. He appeared in six games and had a half-sack against Ole Miss. But an ankle injury slowed him in the spring. The junior Atchison (6-foot-3, 236 pounds) played in the first two games of 2011 before a shoulder injury sidelined him for the year. As a redshirt freshman in 2010, he played in four games. These two resume their spring battle on Friday.

For more up-to-the minute news and analysis from SEC bloggers Larry Hartstein and Daniel Lewis, follow @CBSSportsSEC.