MANKATO — Tom Johnson could be moving into the Vikings’ starting lineup. If that happens, he will arrive with plenty of confidence.

“We’ve got the best defense in the NFL,’’ the defensive tackle said.

Safety Harrison Smith agrees.

“That’s the mindset we have to have,” he said. “That’s what’s in my heart, so I think that’s what’s in Tom’s heart. Everybody knows, though, we still have to show up and actually certify that.”

Smith was one of five Minnesota defensive players to make the Pro Bowl last season. The Vikings were third in the NFL in total defense and sixth in scoring defense, and would have been higher if not for a late-season swoon.

This year, they’re shooting for No. 1 in both categories.

“That’s what we’re going for,” defensive end Danielle Hunter said. “You got to want to be the No. 1 defense.”

The Vikings haven’t been No. 1 in total defense since 1993, and haven’t been tops in scoring defense since 1971. They were No. 1 in both categories in 1969 and 1970 during the “Purple People Eaters” era.

Johnson knows his history, so he’s not about to say this defense is better than the ones Minnesota had back then. Still, Johnson does offer this.

“I think that we’re going to be the best defense that this organization of this era has seen,” he said.

Entering his fourth Vikings season, Johnson didn’t start any games last season but was listed No. 1 at three-technique defensive tackle when the first depth chart came out Monday.

Hunter, tops on the depth chart at left defensive end, is expected to move into the lineup to replace Brian Robison. Last season, Hunter had a team-high 12 1/2 sacks, making him a candidate to be another Minnesota player to make the Pro Bowl.

“We’ll get a couple more in there,” he said.

Joining Smith in the Pro Bowl last season were nose tackle Linval Joseph, defensive end Everson Griffen, linebacker Anthony Barr and cornerback Xavier Rhodes. Joseph brought Hunter to the game in Orlando, Fla., as his guest to give him a preview of what Joseph expects will be in Hunter’s future.

The Vikings’ top two losses on defense were nickel back Captain Munnerlyn, who returned to Carolina as a free agent, and retired weak-side linebacker Chad Greenway.

Head coach Mike Zimmer says he’s confident second-year player Mackensie Alexander can replace Munnerlyn. Greenway played only 39 percent of the snaps last season because the Vikings so often used their nickel package. Emmanuel Lamur and Edmond Robinson are listed as tied on the depth chart at weak-side linebacker. Rookie Ben Gedeon also is in the mix.

The Vikings conclude training camp Tuesday and open the preseason Thursday at Buffalo.

“I feel like we’re trying to be the best defense in the league,” Joseph said. “And doing that we have to come out here in training camp and build a team, so we can be the best. It doesn’t happen overnight.”

Over the past two weeks, Griffen, Rhodes and Joseph signed lucrative extensions, keeping them under contract through 2022. Smith signed an extension last year, locking him up through 2021. Barr, Hunter and linebacker Eric Kendricks are all good bets next year to get big extensions.

Minnesota’s defense had a chance to show off in Saturday night’s practice before 10,500 fans at Blakeslee Stadium. During live drills, the first team often stuffed the offense.

“I 100 percent agree,” guard Alex Boone said of the Vikings having the NFL’s top defense. “Have you seen those guys? They are out to maul people.”