On Monday night, the 49ers defense showed on national television that it has undergone a personality transplant from 2014.
The unit -- shredded by key losses over this offseason of impact players such as Justin Smith, Aldon Smith, Patrick Willis, Chris Culliver and Chris Borland -- was an aggressive, blitzing, shifting group under new coordinator Eric Mangini.
The defense blitzed often and sacked Vikings quarterback Teddy Bridgewater five times in San Francisco’s 20-3 season-opening victory.
Safeties Antoine Bethea and rookie Jaquiski Tartt each came up with sacks on blitzes. Tartt essentially was a wild card who lined up all over the field, sometimes close to the line of scrimmage as a nickel linebacker and sometimes deep.
“It’s like a dream come true,” Tartt told Paul Gutierrez of ESPN.com. “I get to blitz, I get to play (against) the tight end, I do whatever.”
Inside linebacker NaVorro Bowman, who played his first regular-season game and had seven tackles after missing all of 2014 with a knee injury, said it will be fun to play for Mangini, who likes to attack offenses.
“He wants the offense to have to defend us (rather) than us defend the offense,” Bowman told Gutierrez.
Conor Orr and Chris Wesseling of NFL.com wrote that Mangini’s unpredictable approach was the cause of Bridgewater’s subpar night, his worst in 13 career NFL starts. He completed 23-of-31 throws for 231 yards, but had no touchdowns, threw a costly interception late in the game and often came up empty on third downs when he was forced into long situations, couldn’t find a receiver or was hit or sacked.
“Mangini was in Bridgewater’s head all night, dialing up safety blitzes in key situations and taking away his first read,” they wrote. “Bridgewater’s box score looks innocuous enough, but it doesn’t begin to tell the story of his jitters, confusion and poor decision making on third downs.”
The Vikings were just 1-of-9 on third-down conversions.
The 49ers defense also held Vikings running back Adrian Peterson to just 31 yards on 10 carries.
As the 49ers now begin preparing for the Steelers, whom they’ll play Sunday in Pittsburgh, new head coach Jim Tomsula is happy with his defense and Mangini. For one game, at least, many of the question marks hanging over the defensive unit were answered in the affirmative.
“I was very proud of our defense’s performance,” Tomsula told reporters. “Eric Mangini and the defense staff, I felt like it was a well-called game. It was a good game plan. And we’re happy about that. (But) we’ve still got work to do.”