SANTA CLARA, Calif. -- While most the offseason talk was about quarterback Colin Kaepernick's big new contract, the San Francisco 49ers will focus on more problematic issues when they start training camp practice on July 26 at their Santa Clara complex.

And team owner Jed York tweeted there will be "several" opportunities for fans to see the team practice during camp at the new Levi's Stadium.

If those fans watch closely, perhaps they won't need to read the expressions on coach Jim Harbaugh's face to determine how some of these issues are progressing:

--First on the check list is whether a couple of star players are available.

Tight end Vernon Davis may hold out because he wants a new contract. Outside linebacker Aldon Smith had issues in the offseason that may lead to a suspension by the league.

Davis has two years left on a six-year deal that would pay him $4.7 million this year. His deal averaging over $7 million a year made him the highest paid tight end when he signed it. But first New England's Rob Gronkowski received a bigger deal than Davis and then on Tuesday New Orleans' Jimmy Graham signed a four-year, $40 million contract that includes $13 million this year and $21 million guaranteed.

Other issues:

--Cornerback: Gone are former starters Carlos Rogers and Tarell Brown, leaving Tramaine Brock as the loan holdover with significant snaps from 2013.

In the battle are free agent Chris Cook and draftees Dontae Johnson, Keith Reaser and Kenneth Acker. Eric Wright and Perrish Cox were re-signed to modest one-year contracts. Chris Culliver is the early favorite to start opposite Brock, but remains a question mark after missing all of last season with an ACL tear suffered in training camp. Cook saw the most snaps with the first team while the team continued to work Culliver back into football shape slowly.

--Defensive backfield: The 49ers' secondary took a number of big hits this offseason. Last season's starters -- safety Donte Whitner and corners Carlos Rogers and Tarell Brown -- went elsewhere as free agents.

San Francisco addressed safety by bringing in veteran Antoine Bethea of the Colts to pair with standout second-year player Eric Reid. But the team didn't add proven corners.

Only Brock, who emerged as the team's No. 1 corner after coming on as a reserve early in the season, remains from last year's defense. His team-leading five interceptions earned him a new four-year, $16 million deal, making him the team's highest-paid corner.

Returning as a presumed starter is Culliver, a former nickel back who was out injured last year. After that there is a list of maybes: Cook, a second-round Vikings pick in 2010; young veteran Cox; and rookie draftees Johnson (North Carolina State, fourth round), Reaser (Florida Atlantic, fifth round) and Acker (Southern Methodist, sixth round).

Cook, the former embattled Viking who struggled to live up to his second-round draft status, exemplifies the growing NFL trend of big, physical corners. But he ran into trouble both on and off the field during his four seasons in Minnesota.

In 2013, quarterbacks had a 140.3 rating when targeting Cook in coverage, which included nine touchdowns while completing 71.2 percent of their throws. In March of 2012, the Virginia alum was acquitted of domestic assault charges after allegedly choking his girlfriend. The incident led to a 10-game suspension by the Vikings. Cook is hoping a change of scenery and attitude will help resurrect his career.

The 49ers have revamped their wide receiving corps this offseason by adding Stevie Johnson and Brandon Lloyd. But it was a rookie that made perhaps the biggest impact on the field during minicamp.

"Bruce (Ellington) has been amazing out here," Kaepernick said. "He's picked things up very quickly. Good route runner. Very good feel for the game and he's made plays when we've given him the opportunity."

The 49ers have several interesting potential surprises in the depths of their roster, such as former South Carolina running back Marcus Latimore, now two years removed from his second devastating knee injury; and defensive lineman Lawrence Okoye, a football neophyte whose extraordinary athletic ability was on display as a young discus thrower representing Great Britain in the Olympics. This is the second year with the 49ers for each of them.

Add to that potential surprise list outside linebacker Aaron Lynch, a fifth-round draft pick from South Florida. Although he missed some spring workout time with a bad hamstring, the 49ers like this 6-foot-5, 249-pound pass rusher whose skill set is similar to that of Aldon Smith.

Lynch has very long arms (34 inches) and showed flashes of elite talent during his first season of college football at Notre Dame. But a series of personal issues caused Lynch to transfer to South Florida, where negative reports followed him. Lynch's chance to make the team increase significantly due to Smith's legal status and potential suspension from the league.

Speaking of Aldon Smith. The Los Angeles City Attorney's Office did not file a charge against him stemming from his April arrest for making a false bomb threat at Los Angeles International Airport.

Smith will face a hearing on July 30 to discuss the matter, according to spokesman Frank Mateljan of the Los Angeles City Attorney's Office.

"A City Attorney Office hearing is administered by members of the City Attorney's office in lieu of a criminal filing," Mateljan wrote in an email. "Involved parties are scheduled to attend and give their account of the incident. The individuals are then admonished about the applicable laws and given suggestions on how to avoid similar incidents in the future."

Although no action will be taken now, the office reserves the right to file charges up to one year after the April 13 incident.

Smith, 24, has faced a tumultuous year with several off-field incidents. He missed five games after voluntarily checking himself into a substance abuse program, and faces a July 25 sentencing hearing on weapons and DUI charges from two unrelated incidents. He faces the strong possibility of being suspended by the NFL to begin the 2014 season.