The newest 49ers convene this weekend for their first NFL minicamp, where they’ll spend three days running and grunting, as well as dodging the heavy equipment required for that major construction project.

What the rookies won’t do is catch passes from quarterback Alex Smith, who most assuredly would like to participate.

Instead, Smith will have to wait until next week when the veterans take the practice field. Meanwhile, he’s doing what he always does. He’s doing his part to prove, once again, that he can be a successful NFL quarterback.

Never mind San Francisco’s 13-3 record last season, which proves he already has passed that test on most objective grade sheets.

Never mind that he came within a play or two of reaching the Super Bowl, or that he got that close after taking down Drew Brees and the New Orleans Saints.

Smith has spent part of this offseason addressing one area in particular, according to our friends at Comcast SportsNet. He’s concentrating on his mechanics, on his drop, his setup and his delivery. The goal is to make straighter, truer throws, especially downfield.

In short, Smith’s response to a good season, easily the best of his career, is to tackle the fine points necessary to make next season even better.

He could not make a wiser move, for another good season won’t be enough to prevent general manager Trent Baalke and coach Jim Harbaugh from browsing for a replacement.

Smith won’t forget how the brain trust spent a few days sniffing around Peyton Manning. Nor can he ignore the incoming presence of free-agent acquisition Josh Johnson, a four-year NFL veteran (Tampa Bay) who compiled phenomenal statistics under Harbaugh at the University of San Diego.

Smith, who might be the smartest quarterback in the league, can read the room. So he’s sweating the details. He knows he still has outside detractors, and that they will tolerate him only as long as the team is successful.

Moreover, he knows Harbaugh is utterly ruthless in pursuit of victory.

Unhappy with their offensive production, Baalke and Harbaugh this offseason sent a very explicit message to Smith. They got him a bunch of new toys. Randy Moss and Mario Manningham, along with first-round pick A.J. Jenkins, have joined Vernon Davis, Michael Crabtree and Delanie Walker in the pass-catching corps. LaMichael James was hired to be an all-purpose threat.

When I noted recently that San Francisco’s offense and defense played at completely different speeds, Baalke didn’t bother to mount an argument. He also believes this glaring contrast has been addressed.

“Our defense does play at a high level, and plays fast,” he conceded. “We needed to add some pieces to the offense to allow us to do the same thing from an offensive perspective.”

Care to guess who goes under the microscope if this doesn’t translate to considerably more fun — and points — for the offense?

So Smith is in the lab, tinkering with his technique in search of better accuracy.

Smith alluded to this during a recent chat on 49ers.com, saying he has consulted with a quarterback “guru” in Southern California.

“I’m really focused on getting my fundamentals better,” he said. “Really didn’t have time last offseason to do it.”

Well, of course he didn’t have time. He’s never really had the kind of time he has now.

Though Smith previously has attempted to make mechanical adjustments, with varying degrees of success, there always was so much more with which to contend. Always, every year, there was a new offensive coordinator, with new ideas — and a new playbook, with new terminology. That pattern was compounded last season, when the lockout prevented supervised workouts with new coaches, who brought their new playbook.

Though Smith, who turned 28 this week, is preparing for his eighth season, it’s the first during which he can focus almost solely on the little things.

It doesn’t mean he doesn’t have time for his wife and infant son. It doesn’t mean he can’t carve out some time for good deeds, such as joining the search for Sierra LaMar, the Morgan Hill teenager who has been missing since March 16.

What it means is Smith, whose decision-making dramatically improved in his first season under Harbaugh and offensive coordinator Greg Roman, is devoting considerable time to being an appreciably better passer.

You may remember last December, when Harbaugh stood up and said his quarterback deserved to go to the Pro Bowl. Truth is, Smith did not play at Pro Bowl level. He simply had improved enough that future selections were conceivable.

Smith heard what his coach said. He always does. Now he’s out to show he also listens to his coach’s unspoken thoughts.

Contact Monte Poole at mpoole@bayareanewsgroup.com. Follow him at Twitter.com/1montepoole.