SANTA CLARA -- Anquan Boldin looks as polished as ever, and partly because of that, the 49ers' leading receiver is drawing double coverage more than at any other time in his 11-year career.
The next defense focusing on Boldin is the Arizona Cardinals, Boldin's original team for seven years.
Another obvious reason for so much defensive attention on Boldin: the 49ers' enduring search for another wideout to complement him. When tight end Vernon Davis isn't a receiving option, Boldin's job gets only tougher, he conceded.
Said Boldin: "I get a lot more roll-coverage, a lot more double teams. Defenses definitely try to take me out a lot more."
Red-hot cornerback Patrick Peterson will be shadowing Boldin, but the Cardinals might need to provide safety help, especially if Peterson gets beat as he has in past matchups against the 49ers' Michael Crabtree.
"There's a lot of different ways you can play doubles, and he's seen just about all of them this year," 49ers offensive coordinator Greg Roman said. "It's becoming more prevalent, and to be expected, really."
That hasn't forced Colin Kaepernick to ignore his most trusted target. Kaepernick's passer rating is 108.5 on 42 attempts to Boldin, and that rating dives to 27.7 on his 28 attempts to four other wideouts: Kyle Williams, Jon Baldwin, Marlon Moore and Quinton Patton.
"We don't just say, 'Throw it to this guy,' because if he's doubled, that's not good for business, as they say," Roman added. "So the ball's going to go to the open guy. Other guys beside Anquan need to step up."
Mario Manningham, a potential savior as a No. 2 wideout, said he will start practicing next week for the first time since tearing the anterior cruciate ligament in his left knee 91/2 months ago.
Manningham is among those marveling at Boldin's ability to succeed in such a scrutinized role. "I like the way he attacks the ball, no matter if he's open or not," Manningham said.
More often than not, Boldin is getting blanketed by defenses. His only two receptions last game came on the 49ers' opening touchdown drive. "He got doubled quite a bit last week, especially on third down," Roman said.
Boldin's 13 receptions in the past four games match his opening-day total, when he racked up 208 yards and a touchdown against the Green Bay Packers.
That dominant debut temporary alleviated the 49ers' concerns about missing Crabtree, who tore an Achilles in May and is not expected back for at least one more month.
"I don't think Anquan came in to replace anyone. Anquan Boldin came in to be Anquan Boldin," Roman said. "He's never gotten the credit he's due for what a complete football player he is."
Recalling when he got drafted by the Cardinals in 2003 (second round, 54th overall), Boldin said his plans were "to be successful" and his career has since "played out pretty much the way I thought it would." He won his first Super Bowl last season in his third and final year with the Baltimore Ravens, who traded him in March for a sixth-round pick to the 49ers.
He's already faced the Cardinals when with the Ravens, so Sunday's is "just another game," even though he ranks second in Cardinals history with 586 receptions.
Boldin turned 33 last Thursday, and his veteran leadership transcends the playing field. He acts like a coach in the receivers' room, telling his younger counterparts different ways to get open and understand defenses, according to practice-squad wideout Chuck Jacobs.
Said Manningham: "He's polished and knows how to be a professional at any situation here. He's talking, he's speaking out, and he's letting the quarterback know things."
Boldin is such an upstanding role model that coach Jim Harbaugh suggested that one of the NFL's most accomplished receivers ever could become one of the nation's top politicians.
"I think 'Senator Boldin' is something that could be in his future because he cares about people, he's very smart and he's got extremely high character," Harbaugh told Arizona reporters Wednesday on a conference call.
So what is Boldin's diplomatic solution to stymie defense's double-team "shutdown" attempts?
"Just work," Boldin responded. "There's not much you can do. You can try to game plan and coaches move you around a bit, but that's about it."
A look at Anquan Boldin's career receiving numbers:
Year Team Rec Yds TD
2013 49ers 26 393 2
2012 Baltimore 65 921 4
2011 Baltimore 57 887 3
2010 Baltimore 64 837 7
2009 Arizona 84 1,024 4
2008 Arizona 89 1,038 11
2007 Arizona 71 853 9
2006 Arizona 83 1,203 4
2005 Arizona 102 1,402 7
2004 Arizona 56 623 1
2003 Arizona 101 1,377 8
Totals 798 10,558 60
Arizona (3-2) at 49ers (3-2),
1:25 p.m. FOX