Jonathan Gannon is impressed with the 49ers offense, but also expects Eagles fans to have an effect

Jonathan Gannon still has vivid memories from his last experience coaching in a conference championship game at Lincoln Financial Field.

On Tuesday, the defensive coordinator recalled the 2017 NFC title game between the Eagles and Vikings, when he served as a Vikings assistant defensive backs coach. The Eagles handily defeated Gannon’s former team, 38-7, to advance to the Super Bowl.

Gannon is hoping to replicate those results Sunday — this time with the home team — as the Eagles host the San Francisco 49ers in the NFC championship game involving the conference’s top two seeds.

“I was here for a Final Four game, and it was electric, best environment I’ve ever been at or a part of,” Gannon said. “In warmups, [Vikings safety] Harrison Smith looked at me with a look in his eye like, ‘Whoa.’ I said, ‘whoa’ back. You could feel the energy, and it’s awesome. This is one of the best atmospheres that you’re going to get in the National Football League, and obviously being the championship game, it’ll be heightened.

“I thought the energy in the building was just phenomenal ... it’s a tough place to play, and it’s a big advantage for us.”

When it comes to comparing the two home atmospheres in Philadelphia and Minnesota, Gannon boasts a unique perspective considering he was part of the Vikings coaching staff when the franchise opened U.S. Bank Stadium in 2016. Leading into the following season’s NFC title game against the Eagles, the Vikings rallied for a comeback victory over the Saints in what was labeled as the “Minneapolis Miracle” with quarterback Case Keenum connecting with wide receiver Stefon Diggs for a walk-off touchdown reception. According to the Vikings, the noise level for the divisional-round game reached 120.1 decibels, equal to that of a jet airplane.

“When that new stadium got built, that was a really good atmosphere, too,” Gannon explained. “The [Minneapolis] Miracle, that game, then to come here to play. I was like, ‘Wow, I don’t know if there will ever be a stadium more electric than that after Diggs has a walk-off.’ When we were here in warmups — that’s what it was. When we were here in warmups, it was like, ‘Whoa, this is more electric than that place was.’

“I always joke about it with [owner] Jeffrey Lurie and [general manager] Howie Roseman, I’ve always wanted to be a part of a Philly team to play in playoff games at [Lincoln Financial Field] because that’s how it stood out in my mind.”

Limiting the 49ers’ offense is going to be a tall task for Gannon and Co. The NFC West champions have reeled off 12 straight victories, including the past seven under third-string rookie quarterback Brock Purdy. The skill group is led by running backs Christian McCaffrey and Elijah Mitchell, fullback Kyle Juszczyk, tight end George Kittle, and wide receivers Deebo Samuel and Brandon Aiyuk, while the offensive line is anchored by All-Pro left tackle Trent Williams.

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“It’s a big-time challenge. They’re in the Final Four for a reason,” Gannon said. “They’re very well-coached, and they have a lot of really good players. They put them in good situations, and they’re multiple. They do some unique things with their guys because of their skill sets. You start going through, start watching the tape, you look at the paperwork, and then you talk to different people in our building about what do we need to do, and it just keeps coming back. It doesn’t surprise me this is the Final Four game; of course, they’re going to be good in every metric. Of course, they’ve got really good players. I think they’ve got guys at their position that they’re probably the best in the world at their position.

“It’s going to be a big-time challenge, and it’s going to be fun because we’re good, too, and we have some of the best players in the world at our positions. We’ll look forward to that challenge, and we’ll be fired up on Sunday afternoon.”

The 49ers rank fifth in total offense (365.6 yards per game), including eighth in rushing (138.8) and 13th in passing (226.8). Meanwhile, the Eagles rank second in total defense (301.5 yards allowed per game), by being 16th against the run (121.6), and first against the pass (179.8).

One of the Eagles’ top priorities will be limiting the Niners on the ground and also in the open field after the catch. In-season acquisition McCaffrey is a dangerous weapon, who is capable of lining up all across the field. Over 17 games with the Panthers and 49ers, McCaffrey compiled 1,880 total yards and 13 touchdowns.

If the defense is able to contain McCaffrey and the offense can build an early lead, the Eagles would force Purdy into known passing and drop-back situations. That’s typically when the Eagles’ vaunted pass rush tends to feast. The defense compiled an NFL-best 70 sacks, and the unit enjoyed a ton of success against inexperienced and young passers.

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Purdy, perfect record and all, falls into that category.

“He’s a good player,” Gannon said. “He plays extremely fast. He knows where to put his eyes. He gets out of trouble at a pretty good clip, and what I mean by that, you see some free runners or the pocket breaks down and guys have a hard time getting him on the ground. He doesn’t take a lot of sacks. He makes quick decisions. He’s accurate. He gets the ball out of his hand.

“Kyle Shanahan is a really good coach. He knows how to coach the quarterback of what they’re trying to get done with certain plays, and he’s doing that. That’s a reason that they’re playing in this game.”