Frank Gore is only 22 yards short of eclipsing the 49ers’ all-time rushing record.

Short, you say?

“The first time I saw him, I said, ‘Frank, bro, you’re not as tall as I thought you were,’ ” rookie Kendall Hunter recalled Wednesday. “On TV, I watched him a little bit and thought he was a big guy.”

Gore may be 5-foot-9, but he’s proved himself as a big-time running back since joining the 49ers in 2005.

Now he is on the cusp of Joe Perry’s franchise rushing record, and the 49ers (9-2) are on the verge of making the playoffs for the first time in Gore’s NFL career.

To clinch the NFC West, the 49ers must either, (a) trump the last-place St. Louis Rams (2-9) on Sunday at Candlestick Park, or, (b) parlay losses by both the Seattle Seahawks on Thursday night and Arizona Cardinals on Sunday.

The Rams should be a welcome sight for Gore, and not just because they have the league’s worst rushing defense (159 yards allowed per game).

Gore has had eight career games in which he’s rushed for two touchdowns. Four of those came against the Rams.

Is there something about St. Louis that charges up Gore more than other opponents?

“Any time you play a division opponent, it means that much more,” quarterback Alex Smith responded. “But him, he’s fired up every week.”

Limited in practice Wednesday by a lingering ankle injury, Gore is 91 yards shy of his fifth 1,000-yard season in seven campaigns.

He ran for at least 125 yards and a touchdown in four consecutive October games, and he broke the 100-yard mark in a fifth straight Nov. 6 at Washington.

But against the New York Giants, he had six carries for zero yards before injuring his right knee and sitting out the second half of the 27-20 win.

He got back on track with 88 yards in a 23-7 rout of the Cardinals, then managed only 39 yards against a stifling Baltimore Ravens defense in a 16-6 Thanksgiving night loss.

One aspect noticeably absent from Gore this season is his production as a receiver. He has 16 receptions, none for touchdowns. He is on pace for 23 catches, half his total from last season.

“Alex has done a great job of getting the ball down field, and I’m good with that,” Gore said. “We have more success with Alex throwing the ball down the field than just looking at me and checking the ball down.

“It’s more about the team than me and my stats.”

Smith said the 49ers’ new scheme and protections have impacted Gore’s duties.

“Frank is one of the best in the game, I think, in protecting and he takes a lot of pride in that and the way we use him in our protections,” Smith said.

Gore has shared tips with Hunter when it comes to blocking techniques and an uncanny vision.

“As a running back, I feel I bring a lot (of skill), but I’ve learned a lot from Frank,” Hunter said. “He’s great and a future Hall of Famer, and it’s great to have a leader around like that.”

Perry made it to the Pro Football Hall of Fame after setting the 49ers’ rushing record with 7,344 yards in his NFL action (1950-60, ’63).

The 49ers and the NFL don’t recognize the 1,345 yards that Perry accrued in 1948-49 in the All-America Football Conference. The Hall of Fame, however, lists Perry’s statistics from those two AAFC seasons among the 9,723 he totaled in a 16-year career.

Perry, by the way, is listed at 6-foot on his Hall of Fame bio.

Gore is a few inches shorter. He still towers over Hunter: by 2 inches in height and 7,025 yards on the ground.

Shocked by his first up-close look at Gore, Hunter said he’s also learned this: “Size really doesn’t matter.”

For more on the 49ers, see Cam Inman’s Hot Read blog at blogs.mercurynews.com/49ers.