SANTA CLARA -- Unlike so many of the flashy receivers around the league, Anquan Boldin prefers to let his hands do the talking. The 49ers' major offseason acquisition is so tight-lipped that he can strike people as aloof.

"I hear that a lot," Boldin said Friday. "I even hear that from my mom."

Then he cracked a smile. A least for a few seconds.

Most of the time, though, Boldin is all business around the football field. As he pointed out Friday, he has a lot to do this training camp, starting with developing a rapport with quarterback Colin Kaepernick. Boldin said that the rifle throws are the least of his concerns, saying that it doesn't matter "if a guy is throwing 1 mph or 90. The end result has to be the same to me, and that's to catch the football."

The more important work is getting to understand what makes Kap tick. He wants to get to the point where he was with quarterback Joe Flacco (in Baltimore) and Kurt Warner (in Arizona), when a look in the eye was enough to make an adjustment at the line of scrimmage.

Not surprisingly, Boldin likes it better when they don't have to speak.

"There comes a point where you don't have to communicate verbally," Boldin said. "You want to be able to look at the other guy and know what he's thinking."

Though not big on words, Boldin does OK with the numbers. He is the fastest player in history to reach 400, 500 and 600 receptions and the fourth player to amass at least 50 catches in each of his first 10 seasons.

Boldin, 32, last made a Pro Bowl in 2008 but remains a key contributor. He led the Ravens last season with 65 catches for 921 yards.

The 49ers will be counting on him in two fronts: For one, Boldin will have to establish himself quickly as No. 1 receiver Michael Crabtree recovers from an Achilles injury. For another, the veteran will have to help the rest of an untested receiving corps get up to speed.

"The great thing about it is that those guys ask questions," Boldin said. "Those are guys who are hungry to learn, and they are teachable guys. If you say something to them, they take it to heart. I think that's the best part about of it."

  • Defensive coordinator Vic Fangio held off on anointing first-round draft pick Eric Reid as Dashon Goldson's replacement as the starting free safety.

    "Nothing is given," Fangio said. "He's got to go out and earn it."

    Fangio said Craig Dahl, C.J. Spillman and Trenton Robinson comprise the rest of a four-player competition. Asked specifically about Robinson, Fangio credited last year's sixth-round pick out of Michigan State for figuring out just how demanding it is to make it in the NFL.

    "I don't think he felt the urgency last year, and I don't think he was as mature last year," Fangio said. "When he started the offseason, he wasn't talked about much in the mix (at free) safety, but he's done well for himself and put himself into that mix."

    Robinson appeared in only three games as a rookie and contributed one special teams tackle.

  • With a number of read-option quarterbacks lying in wait this season, the 49ers defense will spend more time learning how to stop the in-vogue offense. In contrast to a year ago, the 49ers' first-string defense will spend more time trying to corral Kaepernick during practice.

    Last year, the only read-option quarterback the 49ers prepared for was Tim Tebow, who was then with the New York Jets.

    "So we didn't waste our time working on it against our own offense with our first-string defense," Fangio said. "This year we will, obviously. So it does help having an offense that can run it."

    The 49ers face Seattle's Russell Wilson (Sept. 15 and Dec. 8), Carolina's Cam Newton (Nov. 10) and Washington's Robert Griffin III (Nov. 25).

  • After practice, Kaepernick and running back Frank Gore joined NFL Network analyst Marshall Faulk for separate one-on-one interviews.

  • Defensive tackle Lamar Divens, who sustained head injuries in an alleged attack by 49ers teammate Ahmad Brooks last month, was cleared to practice. Divens (6-foot-3, 325 pounds) will vie for a backup role, with Ian Williams and Glenn Dorsey the top candidates to replace Isaac Sopoaga (Eagles) and Ricky Jean Francois (Colts) in the line rotation.

    Staff writer Cam Inman contributed to this report.