The injury San Francisco 49ers OLB Aldon Smith suffered in the team's preseason opener Friday against Minnesota is not expected to keep him out of the regular-season opener at Green Bay on Sept. 9.

The second-year pro bruised his left hip chasing down Vikings RB Toby Gerhart and remained in the game for a play before leaving for good. He will not play Saturday at Houston. Smith left the team facility Monday with the aide of a cane and walked with a noticeable limp.

“I’m concerned from the standpoint that he didn’t get about 15 more plays that he would have got the other night at outside linebacker," DC Vic Fangio said. "Concerned that he’s missing a good bit of this week’s work, but long term I’m not concerned. But it is a setback in the short term.”

The injury could slow Smith's learning curve as he transitions from pass-rush specialist to complete OLB.

In the meantime, Parys Haralson will rep in with the first-team defense as the starting ROLB -- the job he held in Smith's rookie year.

When asked if Smith's role as an every-down OLB would be in jeopardy if he misses the rest of the preseason, Fangio acknowledged it was a possibility.

“I’m not anticipating that being the case," he said. "We’ll see how it unfolds as we move forward.”

Haralson was 12th on the team in tackles with 39 last year.

Tolzien's success not a surprise: QB Scott Tolzien made a solid push for the No. 3 QB job in the team's first preseason game, completing 10 of 13 passes for 84 yards with a pair of drops.

The performance didn't surprise Fangio.

"I was very impressed, personally, with what Scott did in the game the other night," he said. "But I wasn’t surprised by it because he does that out here on the practice field all the time. Scott did well by himself in the game, but again, he carried over from the practice field to the game.”

Tolzien entered the game before Josh Johnson and could be a better fit to run the scout team due to their differing skill sets. While Johnson shows flashes what made him a starting QB in the league, albeit briefly, Tolzien has been steadier and more reliable.

“He does a good job in reading a defense," Fangio said. "I think he’s got a good command of football, not just offensively but defensively, and he’s got that little extra intelligence that you want in a quarterback.”

Injury notes: TE Delanie Walker injured his right knee in practice Sunday and did practice Monday. LB Ahmad Brooks, NT Isaac Sopoaga, LB Cam Johnson, LB Tavares Gooden, TE Nate Byham and LB Aldon Smith also missed practice for undisclosed reasoned.

Roster moves: The team announced it signed TE Gijon Robinson to a one-year contract, TE Joe Sawyer to a three-year contact and waived G Garrett Chisolm.

Robinson spent 2008-2010 with the Indianapolis Colts, where he started 26 games and caught 31 passes for 240 yards and a TD. He was released after training camp last season by Detroit and spent seven days with the Jaguars before being released on Aug. 2.

Sawyer is a rookie out of Southwestern Oklahoma State, where he caught 76 passes for 782 yards in 21 games after transferring from Snow Junior College in Utah.

Follow 49ers reporter Kyle Bonagura on Twitter: @CBSSportsNFLSF and @KyleBonagura.

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