The San Francisco 49ers ranked fourth in the NFL in total defense last season and second in scoring defense, and there's no question defense is the team's strength.
So it comes as somewhat of a surprise that opposing offenses have moved the ball and scored with relative ease against the 49ers during the preseason. That includes Sunday's 29-24 victory over Denver, in which the Broncos scored on their first three possessions to take a quick 17-0 lead. Broncos quarterback Peyton Manning played less than a quarter but completed 10 of 12 passes for 122 yards and led scoring drives of 23, 83 and 45 yards without a punt or turnover against the 49ers' No. 1 defense.
San Francisco defensive coordinator Vic Fangio says it's not time to panic, though.
"No, not yet," he said Monday. "We just didn't play well enough on certain plays. I think it was a great learning experience for us, in that some of the plays were we broke down, we could have definitely played better. And then in some instances, they just beat us one-on-one. We weren't able to win the one-on-one battles."
It is just the preseason, and the 49ers don't do any specific game-planning for opposing offenses at this stage.
Plus, the 49ers played Sunday's game without Aldon Smith, NaVorro Bowman and Chris Culliver.
Fangio agreed the team might be a little overconfident, perhaps concerned more about the regular season than the preseason.
"I think there is some of that," he said. "The guys are ready to go, that's for sure and get on to playing in the regular season. This is still great time to learn, perfect your craft, excel on your technique and stuff and we have to be able to do that. And we weren't perfect on that the other night by any means."
Fangio was reminded that the Houston Texans and quarterback Matt Schaub had similar success against the 49ers defense in the third exhibition game last season.
"I kind of recall that game last year as being, yeah we got beat, and I don't really remember what the score was, but I saw a lot of good signs in that game, too, that I thought meant good things for going down the road," he said. "And I still see that here, too. It's important that we learn from our technique mistakes and not repeat them.
"[On Sunday] we played the run pretty good, other than the one that popped out of there. Thought we had some good individual efforts. [DT] Justin Smith showed that he's ready to go. Couple other players did also. We just weren't consistent. And I was particularly disappointed in some of the backups' performances after they got in there."
Fangio has been impressed with cornerback Perrish Cox and has been trying to decide how to use him.
"He's a backup nickel right now, a backup corner," Fangio said. "The more three- and four-wide receiver teams that we see, the more he'll get to play. But if he keeps playing the way he's playing and becomes an expert at his craft, we'll find a way to get him in there."
The 49ers have not decided which players will participate in Thursday's final preseason game against San Diego.
"We haven't totally decided that yet. I think it'll be more so on an individual basis than on a unit basis," Fangio said.
According to Comcast SportsNet Bay Area, receiver Ted Ginn, who sprained his right ankle in Sunday's game, had an orthopedic boot on his foot Monday and it's uncertain whether he'll be ready for the Sept. 9 season opener at Green Bay.
Running back Brandon Jacobs was no longer on crutches because of his knee injury, according to CSNBA, and the 49ers hope he can play against Green Bay.