SANTA CLARA -- As part of a mercifully quiet offseason, 49ers linebacker Aldon Smith found time to return to his Missouri roots.

He stopped by his old school, Raytown High, where he spoke to an assembly and signed a jersey for the school's display case. Along the way, he delivered a message that would sound just as suitable for the 49ers as they prepare for Sunday's regular-season opener against the Green Bay Packers.

"I remember him saying: 'Shoot for your dreams. Shoot for your dreams,' " recalled junior Brian Taylor, the backup quarterback for Raytown.

Smith knows firsthand what it means to aim high. He enters his third season as the 49ers' pass-rushing maestro, with the league's single-season sack record within reach. So is a return Super Bowl trip.

Not bad for someone less than a month shy of his 24th birthday.

Six years ago, Smith was playing for Raytown High and "just trying to win the game on Friday," he said. Recruited to the University of Missouri, then drafted by the 49ers, Smith has compiled more sacks in his first two seasons (331/2) than anybody in the 30-year history of the statistic.

That shocks no one who saw him as a teenager.

"I can't tell you we were super surprised," former Raytown coach Ken Clemens said of Smith's NFL success. "We knew he had a special skill."

Raytown High is located about four miles from Arrowhead Stadium, home of the Kansas City Chiefs. The schools' trophy cases don't reflect much special about its football team, aside from one 8x10 photo: Smith's senior portrait.

Across the hall is the basketball team's treasure trove, including a group photo with Smith's 6-foot-4 frame centered in the back row.

"Our football team wasn't that good, so football wasn't my best way to get friends," said Smith. "Our basketball team was really good, so that helped out."

Before he transferred to Raytown his junior year, Smith was known mostly as a hoops player. He lived with his family in Cedar Rapids, Iowa, and played basketball but not football.

When his parents divorced, Smith chose to live with his father, Thurston, near Kansas City, rather than with his mother in Georgia "It was definitely a decision that weighed a lot on my life and how it's turned out," Aldon Smith said.

More decisions awaited him, such as: football or basketball? Clemens recalled that Smith was a "real good" basketball player who specialized in rebounding and defense. "He just couldn't shoot,'' Clemens said.

Smith's father preferred basketball for his son. "But he had to make his own decision,'' Thurston said, "and he made the right one."

In football, Smith excelled on defense, where he had 12 sacks and forced seven fumbles as a senior for a team that finished 3-7. Smith also helped out on offense.

"He was a great tight end in high school," Thurston said. "And I thought he stood out more on offense. But at that level, everyone focuses on offense, anyhow."

Missouri's coaches also saw Smith's two-way prowess during their recruitment of him. So they gave him a choice of which side of the ball he would play. "I felt defense was the way to go," Aldon Smith said. "I was better at it."

Good call. Smith went on set Missouri's single-season record for sacks (111/2) as a redshirt freshman, breaking the standard set by current 49ers teammate Justin Smith.

Drafted seventh overall in 2011, Aldon Smith promptly began terrorizing opposing passers. He had a franchise-record 191/2 sacks last season, all in the first 13 games.

A combination of a torn shoulder labrum, the opposition's increased focus on him, and Justin Smith's triceps injury hindered Smith's late-season production. The 191/2 sacks left him one short of the league leader, Houston's J.J. Watt, and three behind Michael Strahan's league record.

But Smith's contribution to the defense can't be measured by sacks alone.

"I don't think any situation is too big for him," 49ers defensive coordinator Vic Fangio said. "His Atlanta game (for the NFC championship) was as good a game as he played for us last year. He just didn't have any sacks. Even on the last play ... he gave us great rush and affected the play."

Fangio insists there is still more upside. He said Smith still can improve his technique and knowledge of the game, "little things" to raise his and the defense's production.

After a turbulent offseason last year -- getting arrested on suspicion of drunken driving, suffering stab wounds at his own party -- Smith is coming off a quieter 2013 offseason. He tinkered with mixed-martial-arts training and underwent surgery on that torn labrum.

And, of course, there was that trip back to Raytown High and the pep talk he gave to students about shooting for their dreams.

Six years ago, Thurston Smith was the one offering such encouragement to his son.

"As he's matured, he's understanding the game better," the elder Smith said. "With that, and staying healthy and humble, those are ingredients the future Hall of Famers had.

"He always tries to find a way to get better. He's never satisfied. To be in the league a long time, you have to have that mentality. I don't think he, or anyone, is going to be satisfied until he gets a Super Bowl ring."

For more on the 49ers, see Cam Inman's Hot Read blog at blogs.mercurynews.com/49ers. Follow him on Twitter at twitter.com/CamInman.

THE DIFFERENCE-MAKERS

Colin Kaepernick, QB: From Alex Smith's backup to multitalented superstar, Kaepernick's transformation has played out in the national spotlight. Watch Colin throw. Watch Colin run. Watch Colin enter his first full season as a starter.
Aldon Smith, OLB: Unable to get a sack over his final six games, Smith is eager to return to his record-setting form (331/2 sacks in his first two years). He could become the franchise's first player to win the NFL sack title.
Anquan Boldin, WR: A sixth-round pick is all it took to acquire the proven veteran. His arrival took on savior-like status once Michael Crabtree tore an Achilles on May 21.
Eric Reid, FS: Dashon Goldson's successor came with the 18th overall pick, and he's worked his way into the opening-day lineup. Bryant Young (1994) was the last first-round pick to start Week 1 as a rookie for a 49ers team coming off a winning season.
Frank Gore, RB: At age 30, Gore insists he's not ready to pass the proverbial torch to a younger back. He'll look to make the most of what could be his final season, though he's never mentioned retirement.
-- CAM INMAN

BIG DATE:
SEPT. 15 -- At Seattle
The 49ers-Seahawks rivalry has intensified with a series of cat-and-mouse transactions and verbal barbs since the Seahawks routed the visiting 49ers 42-13 last Dec. 23. Like that game, the division won't be won or lost in this rematch. But it will set the 2013 tone.

what they're saying
Mike Sando, ESPN.com: The 49ers underwent a fair amount of roster turnover by their standards, but they remain formidable at quarterback, running back, the offensive line and defensive front seven. This team still can win it all with some better injury luck. Prediction: Second in NFC West
John Clayton, ESPN.com: To win the division again, the 49ers have to sort out problems at wide receiver while they wait for Michael Crabtree to return to the field late in the season. Prediction:
Second in NFC West


Online extra
Scan this code with a smartphone to view a photo gallery of Aldon Smith's hometown or go to http://photos.
mercurynews.com.