Last March 5, Von Miller sent out a tweet proclaiming the Broncos would win the Super Bowl.

“GUARANTEE IT,” Miller tweeted.

Now, 10½ months later, Miller was in the middle of the Broncos’ victorious locker room Sunday, leaning on crutches, an enormous brace covering his right knee.

“One step away,” Miller said.

The Von Miller-less Denver defense is a big reason the Broncos will play in Super Bowl XLVIII. How did this happen? Denver’s defense had struggled all season when it was healthy. Then it lost Miller, Kevin Vickerson, Rahim Moore, Derek Wolfe and Chris Harris — all starters — to season-ending injuries and suddenly it plays Super Bowl-worthy?

“The magic moment was a guy like you doubting us and calling us average,” said Broncos defensive end Shaun Phillips. “You said we were an average-at-best defense. I spread it amongst the locker room and guys started playing better and started stepping up.”

Don’t know why Phillips was so defiant. Though 14 games this season, the Broncos ranked 25th in the NFL in total defense (374.6 yards) and 26th in points allowed (26.6). In a 32-team league, calling a defense ranked 25th and 26th “average at best” is putting it nicely.

“After we lost to San Diego (in Denver on Dec. 12), the defense got together right here in this spot and we just decided to air everything out, say what you have to say,” said Broncos defensive tackle Terrance Knighton. “Right here. We said it’s time to get this thing rolling. It’s time to peak.”

The Broncos finished the regular season by giving up only 13 points to Houston and 14 fourth-quarter garbage points to Oakland. OK, but that was Houston and Oakland. Then, in the playoffs, the Broncos had San Diego shut out through three quarters and allowed only three points to New England through three quarters.

All of this after losing Miller early against Houston and Harris late in the playoff victory over San Diego.

“I’m aware of who we lost,” said Broncos defensive coordinator Jack Del Rio. “We don’t spend a lot of time feeling sorry for ourselves. We’re aware of it. But we’ve got a lot of good guys behind them.”

This is one of Del Rio’s best coaching jobs.

“He challenged us, but he’s with us,” said speedy linebacker Danny Trevathan. “Coach Del Rio is a good man. We had our ups and downs, but I believe in that man. I believe in his scheme, and he led us here.

“People want to speak bad about our defense: ‘(New England is) going to run the ball, they’re going to have their way. It’s going to be a high-scoring game.’ We just said, ‘You keep talking, we’ll keep playing.’ “

And so, the Broncos are in position to fulfill Miller’s guarantee come Feb. 2.

“I feel great,” Miller said. “I’m going to be able to play in the Super Bowl. I’m going to hit the rehab hard and be ready to go.”

This time, instead of a guarantee, he laughed.