San Francisco 49ers

On 49ers: Story lines to follow into training camp as team concludes spring workouts

S The spring semester is over for the 49ers and school’s out until training camp begins next month. Here were the top story lines for the just-ended sessions:

Absences: First, let’s be realistic. That Vernon Davis and Alex Boone skipped a mid-June minicamp is not going to cause the pillars of the 49ers organization to shake and crumble. Plenty of veterans – from Frank Gore to Justin Smith – didn’t take any snaps during practices this spring. It’s June. It’s not a big deal.

If the holdouts last into training camp and beyond, however, that would be significant.

Of the two, Boone has the better argument for why he deserves a raise. But he lacks leverage. The 49ers have an abundance of interior offensive linemen, including seldom-used Joe Looney, who filled in at right guard throughout the spring.

Davis has a weaker argument – he’s the second-highest-paid 49er in 2014 – but he has leverage. He’s a huge part of the offense, he’s its only deep threat and his backups aren’t close to being able to make up for his loss.

When it comes to Davis’ situation, keep an eye on New Orleans tight end Jimmy Graham, who feels low-balled by the Saints. If Graham wins his current grievance hearing and gets paid more like a top wide receiver, Davis’ argument improves.

If Graham loses and gets paid at the rate of all the other top tight ends – including Davis – Davis ought to return with helmet in hand. A couple of 60-yard touchdowns and all will be forgotten.

Passing offense: Coaches continue to drop big hints that the 49ers will be more pass happy this season than in the past. The team’s stable of receivers – as stocked as it’s been since Terrell Owens and Jerry Rice were in the same meeting room – suggests that’s possible.

But can a leopard like coach Jim Harbaugh change his spots in one offseason? His offenses always have featured a strong rushing attack, and most have been notable for their use of multiple tight ends, not the output of the receivers.

The guess here is that the 49ers will throw more and use more three-receiver formations than they have in the past. But considering how sparingly they’ve used that formation until now, an increase won’t necessarily mean they’ll be putting the ball in the air as much as even the average NFL team.

Vic Fangio, the team’s frank-speaking defensive coordinator, threw a bucket of ice water on the notion of a 49ers aerial assault when he was discussing getting repetitions for his nickel cornerbacks, who see practice time when the offense uses three or more receivers.

Said Fangio: “It’s hard to get three nickel (cornerback candidates) a lot of work in these types of practices, particularly against our offense that doesn’t use a lot of three-wide receiver sets.”

The 2013 “rookies”: The two most prominent members of the 49ers’ 2013 draft didn’t play a single snap last season. That means that 2014 is effectively Tank Carradine’s and Marcus Lattimore’s rookie year.

Running back Lattimore is still coming back from the devastating knee injury he suffered in college. The biggest date on his calendar will be July 26, when the 49ers have their first padded practice. Lattimore will surely take his first hit since the injury occurred Oct. 27, 2012, while playing for South Carolina.

Defensive end Carradine is further along. He practiced with the first-team offense – in place of Smith – and likely will serve as Smith’s backup this season. A reminder: Smith turns 35 this season and will count $6.4 million against the salary cap next season.

Cornerback concerns: The diciest position on the team? It has to be cornerback. Longtime starters Tarell Brown and Carlos Rogers are both in Oakland now and their presumed replacements, Tramaine Brock and Chris Culliver, have 13 career starts between them.

Of course, back in 2011 neither Brown nor Rogers was highly regarded, either. But the combination of secondary coach Ed Donatell and a talented front-seven defense helped them become a solid tandem. Brown finished with four interceptions in 2011; Rogers had six and went to the Pro Bowl.