Defensive keys for Denver

It was all about Peyton Manning last week when he enjoyed a masterful debut as a Denver Bronco in a 31-19 home win over Pittsburgh.

Manning’s comeback overshadowed a strong performance by a Denver defense that continues to improve. But we need to keep on an eye on Denver’s defense. If this unit is as timely and as aggressive throughout the season as it was last week and Manning stays hot, the Broncos could be a team to watch deep into the postseason.

The Denver defense will get a good test on ESPN’s “Monday Night Football” at Atlanta in Week 2. The Falcons’ offense was potent in a 40-24 win at Kansas City. Here are five keys for the Denver defense in this game:

1. Von Miller: We recently examined what it would take for the second-year linebacker to become a complete player. After one game in 2012, it seems like the 2011 NFL defensive rookie of the year is well on his way to becoming the total package. If Miller plays Monday night the way he played against the Steelers, Denver will be in good shape. Miller had two sacks, and he was all over the field all the time. Miller’s performance was the buzz in the press box in Oakland on Monday night before I covered the Chargers-Raiders game. People in the AFC West are worried about how good Miller is becoming.

2. The new guys: I was struck last week by the terrific play of several additions to the defense. Denver went from being the No. 32-ranked defense in the NFL in 2010 to the No. 20-ranked team. The front office felt the need to continue to improve in the offseason and made some nice upgrades, which showed in Week 1. The new players who stood out last week were rookie defensive end Derek Wolfe and free-agent pickups cornerback Tracy Porter and safety Mike Adams. All three appear to be difference-makers. And they will be vital against the dangerous Falcons.

3. Create turnovers: The Broncos' defense needs to strike again this week. A 43-yard interception return for a touchdown by Porter sealed the win last week. Atlanta is going to do its damage, but if Denver can come up with some turnovers and another score, it can pull off the upset. Atlanta QB Matt Ryan has to be rattled and kept honest or he will pick apart any defense, as he did last week against the Chiefs.

4. Get off the field on third down: The Steelers were 11-of-19 on third-down conversions last week, and Pittsburgh quarterback Ben Roethlisberger connected on some big plays on third down. It was one of the reasons the Steelers were leading in the second half and why they held the ball for virtually a whole quarter. Denver has to shut down Ryan on third down better than it did Roethlisberger.

5. Contain Tony Gonzalez: Pittsburgh tight end Heath Miller made an impact last week -- he had four catches for 50 yards. It seemed as though Pittsburgh thought it could exploit Denver’s defense on tight end routes. Expect the Falcons to try to get the ball in the hands of the still-potent Gonzalez often. Gonzalez was a longtime Broncos killer with Kansas City, where he spent his first 12 NFL seasons. Asked about Gonzalez this week, Denver cornerback Champ Bailey said this with a laugh: “I’m so tired of this guy. He never stops. He creates so many problems because he’s so savvy, and his experience, it shows every week.” Denver has to do everything it can to prevent Gonzalez from taking over.