Glendale, Ariz. --

Frank Gore said he wasn't injured.

And 49ers head coach Jim Harbaugh also said his running back wasn't hurting.

The obvious question: Why did Gore have only 10 carries in San Francisco's 21-19 loss to the Cardinals on Sunday?

The 10 carries were the fewest he has had in a game in which he didn't leave with an injury since he had nine in a loss to Seattle on Dec. 6, 2009.

"Whatever personnel coaches call, that's what I've got to go by," said Gore, who went over 1,000 yards for the fifth time in his seven-year career.

Gore, who has been limited in practice since sustaining an ankle injury in a win over the Giants on Nov. 13, appeared healthy enough. He had 72 yards - averaging 7.2 yards a carry - and scored on a 37-yard run in the third quarter. He had two more carries than backup Kendall Hunter, but Harbaugh said there was no plan to limit Gore's workload, saying the 49ers had a pass-first game plan.

"There was no pitch count," Harbaugh said. "We were doing our best to move the ball, convert, pick up those first downs, and we fell short."

On the 49ers' final drive, they had a 3rd-and-1 at their 41-yard line with 2:14 left and no timeouts remaining. They finished the drive with two straight incompletions as Gore watched from the sideline.

Harbaugh was asked about the game-ending play-calling.

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"I don't want to get into the, 'You should have run it when you threw it; why didn't you throw it when you ran it?' " Harbaugh said. "We tried to pick up the first down. We were in two-minute mode, and we're trying to move the ball to get into field-goal range."

Staley injured: Left tackle Joe Staley sustained a head injury - typically NFL-speak for a concussion - in the first quarter and was replaced by Alex Boone.

Staley appeared to get knocked woozy on the 49ers' first play. He stayed in the game after struggling to his feet, but exited shortly thereafter.

The sacks keep on coming: San Francisco allowed five sacks, raising its total to 18 sacks allowed over the past three games. Another sack of Alex Smith was erased by a facemask call on Arizona safety Adrian Wilson.

Run defense remains dominant: The 49ers became the first team since the 1920 Decatur Staleys not to allow a rushing touchdown in the first 13 games of a season.

San Francisco also set a franchise record by not allowing a rushing touchdown in 14 straight games, a streak that extends to last year.

Arizona running back Beanie Wells had a season-low 27 yards on 15 carries.