Intrigue surrounds 49ers starting spots (w/video)

The 49ers kick off training camp with another stacked and established roster, and as usual few starting spots are in doubt. But there is at least some intrigue. Injuries and right guard Alex Boone's holdout make the summer competition a bit spicier than in recent years. The first practice is at 2:30 p.m. today. Here are the top battles:

INSIDE LINEBACKER

The 49ers won't rush NaVorro Bowman's recovery from an ACL injury, and the smart money is on him returning after the team's Week 8 bye. His absence creates a good competition among four players with little – or no – NFL experience. Michael Wilhoite, who started two games in place of injured Patrick Willis last year, will get the first shot at the job. He'll be challenged by third-round pick Chris Borland, second-year player Nick Moody and undrafted rookie Shayne Skov. Skov's advantage: He's familiar with the defense from his days at Stanford and is familiar with defensive coordinator Vic Fangio, his defensive coordinator with the Cardinal in 2010.

RIGHT GUARD

Boone, who averages $1.6 million in salary, is the 43rd-highest-paid guard in the NFL, and he certainly has outplayed his contract. But his negotiating stance is undermined by the long line of players ready to take over his starting spot. Atop that list is Joe Looney, a 2012 draft pick who filled in for one game at right guard when Boone was needed at tackle. Looney played well in that game, and he will be eager to grab a role in the offense after being lightly utilized his first three seasons. Other options include veterans Jonathan Martin and Adam Snyder. Both also can play tackle, giving them added value when it comes to roster spots. Rookie Marcus Martin, a third-round draft pick, is another possibility. However, he likely will spend more time competing with Daniel Kilgore at center.

RUNNING BACK

It's arguable that the 49ers haven't had as talented a group since Joe Perry, Hugh McElhenny and John Henry Johnson graced the team's backfield in the 1950s. In coach Jim Harbaugh's offense, however, there's nearly always only one tailback on the field at a time. That will be Frank Gore, who is entering his 10th, and perhaps final, season in San Francisco. The real competition will be among his backups. Two young runners, Marcus Lattimore and rookie Carlos Hyde, a second-round pick, have captured the fans' imagination. Both are big-bodied, tough runners who put up huge numbers in big-time college conferences. But barring injuries, their impact likely won't be felt until 2015. Kendall Hunter has been the 49ers' change-of-pace runner the last three seasons. His small size belies his straight-ahead running style, and no one on the team hits the hole as quickly. And LaMichael James' role likely will be similar to what it was last season: He'll primarily be a return man with perhaps a few snaps on offense every so often.

NICKEL CORNERBACK

Carlos Rogers won this role in 2011 because of his smarts and his experience. Rogers is with the Raiders now, and the 49ers must break in a new player who can cover the opponent's slot receiver. The 49ers drafted Jimmie Ward in the first round to handle this job, something he did at Northern Illinois. The team loves Ward's coverage skills and his willingness to level opponents. But Ward sat out spring drills because of a foot injury and must play catch-up in camp. If he is still behind when the season begins, the role could go to veteran Perrish Cox, who filled in for the injured Rogers during last season's playoff run. Another option is second-year player Darryl Morris, an undrafted rookie last year who caught on because of his combination of intelligence and blazing speed.

DEFENSIVE LINE

Harbaugh has called this a 'position of strength' and it's perhaps the deepest on the 49ers' roster. But therein lies the problem: Which talented linemen to keep? Justin Smith, Ray McDonald and Glenn Dorsey are the starters. And last year's second-round pick, Tank Carradine, appears to be Smith's heir apparent at right defensive end. After that, Demarcus Dobbs, Tony Jerod-Eddie, Quinton Dial, Kaleb Ramsey, Mike Purcell and Lawrence Okoye will compete for the last two or three spots. Nose tackle Ian Williams could start the season on the physically unable to perform list.