SANTA CLARA — The offense was stagnant, Alex Smith was ineffective and the offensive line was completely overmatched.

Few would have thought that the San Francisco 49ers team that opened the Jim Harbaugh era with an exhibition dud at New Orleans would be playing the Saints five months later with a spot in the NFC championship on the line.

“It’s not even the same team,” left tackle Joe Staley said. “There’s so much more confidence. We’re so much more sure of ourselves and the schemes and what we’re doing.”

There were few signs of the remarkable turnaround Harbaugh has engineered in San Francisco in that 24-3 loss at the Superdome as the 49ers were completely overwhelmed by New Orleans’ heavy blitz package.

With no offseason because of the lockout and just two weeks of practice to implement a new system, San Francisco failed to get a first down on its first four drives as the first-team offense never got started. In the first half, the Niners allowed six sacks and completed four passes while collecting as many penalties (five) as first downs. Smith went 2-for-7 for 10 yards and Harbaugh even said after the game that rookie Colin Kaepernick would get a shot to compete for a starting job.

That seems a lot longer than five months ago now.

Smith had by far his best season as a professional. He set career highs in completion percentage (61.4), yards passing (3,199) and passer rating (90.7) while playing mostly mistake-free ball to help the 49ers go 13-3 and win the NFC West.

The offensive line gelled to spark a strong running game by Frank Gore as the offense did just enough to support one of the league’s top defenses and special teams units.

“We’re really improved,” center Jonathan Goodwin said. “At that point we had maybe two weeks of practice. It was tough. We didn’t want to make any excuses. It’s tough as a line to not play together. Experience playing together is valuable.”

Much was made after the game about a report that Saints coach Sean Payton went against convention with a heavy blitz package in the first preseason game because he was upset Harbaugh did not call him before the game so there could be a “gentlemen’s agreement” to how the teams would approach the exhibition game.

Harbaugh said he even asked his brother, Ravens coach John Harbaugh, about whether that was proper protocol.

“He wasn’t aware of all that,” Jim Harbaugh said. “And even if there was, we wouldn’t do it, anyway. We ask no quarter, we get no quarter. That’s how we approach things.”

While many of the Niners players expressed surprise at the unusual strategy for a preseason game, Goodwin knew it was coming after seeing defensive coordinator Gregg Williams up close while playing the previous five seasons with the Saints.

“First practice in training camp Gregg blitzes. It wasn’t a surprise for me. That’s what he likes to do,” Goodwin said. “One thing about this league is you have to learn from your mistakes. Fortunately for us, at that time it was a preseason game, a game that didn’t count against us. Hopefully, we’ve learned from some of those mistakes and can apply them in the future.”

The 49ers will need to handle the blitz better this week. According to STATS LLC, the Saints had the second most blitzes in the league this season with 365, trailing only Green Bay. The plays were effective, too, as New Orleans held opponents to a 48.1 percent completion percentage against the blitz with 24 sacks and five interceptions on 316 throws.

The Niners did well most of the season against pressure, with Alex Smith going 91 for 153 for 1,116 yards, eight touchdowns, one interception and a 96.7 passer rating. But they allowed 21 sacks, including 13 in the final six games.

But the Saints are different from most blitzing teams. They have 15 players who have been credited with sacks this season, led by safety Roman Harper’s 7.5, making it difficult sometimes to know where the pressure is coming from.

“Their blitz schemes are a little bit different because they bring a lot more DBs, secondary guys instead of linebackers,” Staley said. “We have to do a great job just identifying and preparing all week.”



Notes: Harbaugh said the team would not make a roster move on TE Delanie Walker, whose jaw was broken in two places in a win at Seattle on Dec. 24. Harbaugh said Walker has “great powers of healing” and would not rule him out for Saturday. ...  Tuesday is the 30th anniversary of “The Catch” — perhaps the most famous moment in 49ers history. Harbaugh recalled watching Dwight Clark catch the game-winning pass from Joe Montana in the NFC championship game against Dallas with his father, who was then as assistant coach at Stanford. “Glad I witnessed one of the greatest plays in the history of the game,” he said.