The 49ers' defense did not game plan specifically for Sunday's preseason game against Denver, but defensive coordinator Vic Fangio wasn't ready to use that as an excuse for the first-team's poor showing.

With the starters in the game, minus LBs Aldon Smith and Ahmad Brooks, Denver scored on all three of its possessions -- two TDs and one FG.

"We were playing [against] stuff that we play all year-round," Fangio said. "There was just nothing special, and maybe we didn’t have our guys alerted to their offense as much as you would in the regular season. But no, you’re still disappointed in the results because all the defenses we played yesterday are things that we’ll carry into each and every game.”

San Francisco returns every starter from the fourth-ranked defense in NFL but has struggled in each of its first three preseason games.

The key word there? Preseason.

Fangio said the team is ready to get into the regular season.

Despite the poor showing, it wasn't all doom and gloom. Fangio acknowledged the team played well against the run and that Justin Smith is ready to go.

Last week, Fangio said they were looking for the backup safety situation to clear up and, so far, that hasn't happened.

“I think Trenton Robinson made some improvements. [Darcel] McBath’s been improving some and getting more comfortable in our system," Fangio said. "I think C.J. [Spillman] was up and down a little bit the other night, but he still, over the long haul, has improved since the beginning.”

Fangio didn't mention rookie Michael Thomas, who survived Monday's first round of cuts but is still listed at No. 4 on the depth chart at strong safety.

Bakhtiari mum on head injury: OLB Eric Bakhtiari was nondescript when asked about the head injury he suffered in Sunday's preseason game against Denver. Bakhtiari, who has a history with concussions, would not confirm if it was ruled a concussion.

His status for this week's final preseason game against the Chargers is also unclear.

Asked if he will play against the Chargers, Bakhtiari said: "I think so. I haven't been told either or. I plan on going out and having a great second practice today, great meetings and going out and doing everything that's asked of me all the way leading up to the game on Thursday."

Bakhtiari is a candidate for the 53-man roster, if the team decides to keep four OLBs. He does not have any practice-squad eligibility remaining.

Ginn walking with a boot: WR <player idref= Jr. walked through the locker room with a boot on his right foot Monday. He sprained his ankle in Sunday's game against the Broncos, and his status for the season-opener against Green Bay is unknown. Ginn will not play Thursday against the Chargers.

If Ginn is unable to go when the season begins, WR Kyle Williams would be expected to handle punt-return duties. RB Kendall Hunter is listed as the No. 2 on kickoff returns.

Dobbs on crutches: DL/TE Demarcus Dobbs is walking with the help of crutches after suffering an apparent lower leg injury against the Broncos. The severity of the injury is not clear.

Jacobs off crutches: RB Brandon Jacobs is no longer using crutches but is walking with a noticeable limp. He left the 49ers' second preseason game with a knee injury and is expected back early in the regular season.

Owusu happy to be back returning kicks: Undrafted rookie WR Chris Owusu found himself in a familiar spot Sunday when he went on to return a pair of kickoffs against the Broncos. He didn't get a chance to return either; both kicks sailed through the back of the end zone. But he was happy to be back in a familiar spot.

"It was one of the best feelings I've had in a long time to go out there and be back there seeing 10 guys in front of you that are willing to block and willing to sacrifice their bodies for you," Owusu said. "Hopefully I'll get some opportunities to be back there again."

When healthy at Stanford, Owusu was one of the most dangerous kick returners in college football. He returned three kickoffs for TDs in his sophomore year and averaged 26.7 yards per return in 80 career chances.

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

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