SANTA CLARA – Last season, come-from-behind wins were Alex Smith's forte.

The 49ers quarterback had six of them, including impressive road wins against Philadelphia and Detroit and at home in the playoffs when he twice led the offense down the field for go-ahead touchdowns against the Saints.

This season, the 49ers' passing offense is better overall than it was a year ago. The players have had a full offseason to learn the playbook, Smith has more weapons, and his protection has improved.

But despite the improvements, the offense – and the passing game in particular – hasn't functioned as well when the 49ers have trailed in the second half this season.

All four of Smith's interceptions have been in losses to the Vikings and Giants, and three have come when the 49ers were attempting a comeback. Smith's passer rating in the two losses is 62.6, compared with 118.2 in the 49ers' four wins.

Why can't Smith and the offense re-create the magic from last season, given all the advantages the 49ers have this year?

"I think in both games we had some things that kill drives, whether it be a penalty, a tipped pass or missed assignment or anything," center Jonathan Goodwin said. "I think that stands out in both of those games. When you're playing against a pretty good defense, you can't have those types of things happen on offense."

Indeed, penalties preceded both of Smith's second-half interceptions Sunday.

Smith, who threw into the teeth of the Giants' coverage both times, said Monday he was "really kicking myself" for not throwing the ball away.

"To me, the two interceptions late were the ones I thought about the most," Smith said. " It's third down and you're trying to make a play, but you're really making matters worse. You've got to see the bigger picture there. Make good decisions in both those cases."

The opponent, of course, also can squash a comeback.

The Vikings and Giants both have excellent defensive lines that generate pressure with only four pass rushers. That allowed them to clog passing lanes, something New York's defense did expertly Sunday.

"They don't have to bring pressure to get home," Smith said. "They've got a bunch of D-linemen that can all get after the pass. So it's tough. They're tough when they get a lead like that."

Coach Jim Harbaugh on Monday went with an Old West theme, likening his team's lopsided loss to a cowboy being bucked from his mount.

"Dust off and let's ride," Harbaugh said. "We've got a ballgame, a football fight coming."

The horse that arrives Thursday, however, has a lot of the same ornery characteristics as the one the 49ers faced Sunday. The Seahawks rank fourth in the NFL in defense, are second against the run and have 17 sacks, tied for sixth in the league.

Goodwin and the 49ers watched in a Youngstown, Ohio, hotel when the Seahawks sacked Green Bay's Aaron Rodgers eight times in the first half in Week 3.

"That tells me right there, they've got a pretty good defensive line," Goodwin said. "We played two tough games against them last year. So I know they can get after the quarterback and they have a defense that's played well for the last year at least."

Said Smith: "In some way, it is nice to have a short week. We've got to move along from this one and get ready for a tough division game."

Injury update – Harbaugh offered no timetable for offensive tackle Joe Staley's return from a concussion, saying the left tackle saw a neurologist Monday per league protocol and his return is up to the medical staff.

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