SANTA CLARA, Calif. -- San Francisco 49ers tight end Vernon Davis said Thursday he plans to attend next week's mandatory minicamp after missing organized team activities and costing himself a $200,000 workout bonus.

"It's mandatory, so I should be there, for sure," Davis said in a radio interview.

Davis accounted for 13 of the team's 21 receiving touchdowns in 2013, not including two key touchdown catches in the postseason. He became the first tight end in league history to have two seasons of 13 touchdowns.

Davis reportedly missed OTAs because he wanted a new contract despite having two seasons remaining on his current deal. When signed his five-year, $36.75 million extension in 2010, he instantly became one of the league's highest paid players at the position. Three seasons into the deal, he remains the third-highest paid tight end in the league with his $7.35 million annual salary.

While Davis should be in attendance next week, at least one teammate is expected to be absent.

Right guard Alex Boone plans to skip the three-day minicamp, Pro Football Talk reported Thursday night. Skipping the mandatory sessions would cost Boone $70,000, and he already is out $50,000 for skipping the offseason program, according to the report.

Boone, 27, started each of the team's 38 games the past two seasons, including the postseason.

--Offensive lineman Jonathan Martin returned to practice this week after a 3 1/2 week bout with mononucleosis. The 49ers traded for the Miami Dolphins' former second-round pick this offseason in exchange for a late-round draft pick in next year's draft.

"(Martin) got off to a good start and the mono hit. Now he's back in there," 49ers head coach Jim Harbaugh said.

The 49ers expect Martin to win the "swing tackle" job behind starters Joe Staley and Anthony Davis. But with left guard Mike Iupati entering a contract year and right guard Alex Boone absent while he hopes to get a new contract, the team is hoping Martin could learn to play guard and potentially be an option on the interior down the road.

"It's a lot of information," said Martin. "It's some new learning. I think, if needed, I'll be able to play."

--The 49ers are loaded at running back with Frank Gore, Kendall Hunter, LaMichael James, second-round pick Carlos Hyde and "red-shirt" rookie Marcus Lattimore.

The nature of OTAs makes it tougher to gauge the competition without contact, but for Harbaugh, it's still time well spent when it comes to evaluating his ball carriers.

"Assignment, vision, understanding of the protections and who their keys are in the run game, and their athletic ability, the way they run, cuts," Harbaugh said when asked what he looks for in his running backs at this point in the offseason.

Lattimore could be the biggest wild card of the group. He was hampered earlier in OTAs with a hamstring injury but has since shown improvement. Coming off his gruesome knee injury in which he tore three ligaments while at South Carolina, he remains an unknown commodity with the pads off.

"(Lattimore is) getting better every day. Noticeably making good, consistent improvement." said Harbaugh.

--After spending most of the regular season at the bottom of the NFL in passing statistics, the 49ers did everything they could to add to their receiving corps this offseason, including trading for Stevie Johnson, drafting Bruce Ellington and signing Brandon Lloyd off the street after being out of football in 2013.

"It's been a good offseason in that regard," Harbaugh said. "Everybody feels now like they belong here. We've been here numerous weeks and they know where to go, they know what they're doing and I think we can make some real strides right now. Pleased with the job everybody's doing right now."

Last year San Francisco went without two of their top three receivers -- Michael Crabtree and Mario Manningham -- for a majority of the regular season. Now with the three new additions and the expected development of second-year wideout Quinton Patton, Harbaugh's offense could have a drastically different look this season to pair with one of the league's best running attacks.