For all but one bad day in mid-January when they couldn’t stop Aaron Rodgers, the Dallas Cowboys were the second-best team in the NFL last year and best in the NFC.

And the Cowboys were dominant on both sides of the ball in their opener last week against the New York Giants.

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Make no mistake, the Broncos will find out how good they are Sunday when they host the Cowboys (2:25 p.m. kickoff) at the eventually to be renamed Sports Authority Field at Mile High. The Cowboys are favored by 1 to 3 points.

It says here the Cowboys are the better team, but the Broncos can still win because they appear to be a decent team that is playing at home.

Here are 9 keys to the Broncos pulling off a home upset and defeating the Cowboys:

1. Contain Ezekiel Elliott

Ezekiel Elliott #21 of the Dallas Cowboys carries the ball against B.J. Goodson #93 of the New York Giants and Romeo Okwara #78 of the New York Giants in the fourth quarter at AT&T Stadium on September 10, 2017 in Arlington, Texas. 

You can’t stop him as he’s had 15 consecutive regular-season games with at least 80 yards rushing. He can break the NFL record streak he tied last week with Marcus Allen with another 80 yards plus against the Broncos.

Let him have his 80. But force the Cowboys to play from behind so he can’t get 100 or 120.

Elliott’s rushing exploits has helped make second-year quarterback Dak Prescott a much better passer. So stop Zeke and the Broncos may have a chance to stop the Cowboys.

2. Protect Trevor Siemian

Quarterback Trevor Siemian #13 of the Denver Broncos is tackled by Corey Liuget #94 and defensive end Joey Bosa #99 of the Los Angeles Chargers in the third quarter at Sports Authority Field at Mile High on September 11, 2017 in Denver, Colorado. 

DeMarcus Lawrence, who had 2.0 sacks and another tackle for loss last week in a stifling Cowboys’ defensive performance against the New York Giants, will primarily line up opposite Broncos’ right guard Menelik Watson, who struggled in pass protection last week against the Los Angeles Chargers’ Melvin Ingram and Joey Bosa.

The Cowboys are vulnerable in the secondary with cornerback Orlando Scandrick out and safety Byron Jones gimpy with a groin strain. Siemian can have success downfield if he gets time.

It appears Broncos right guard Ron Leary is on schedule to play against his former team after he cleared the concussion protocol Saturday.

3. Unleash the speed

Wide receiver Isaiah McKenzie #84 of the Denver Broncos returns a kick in the second quarter of the game abasing the Los Angeles Chargers at Sports Authority Field at Mile High on September 11, 2017 in Denver, Colorado

This primarily means get the ball to rookie speedster Isaiah McKenzie on offense, whether he’s a running back or receiver. Broncos’ head coach Vance Joseph said earlier this week he hopes to dip into the package of plays the team has for McKenzie and rookie running De’Angelo Henderson, neither of whom had an offensive snap in the opener against the Chargers.

4. Unleash Von Miller

Tom Brady #12 of the New England Patriots tries to evade a tackle by Von Miller #58 of the Denver Broncos in the first half in the AFC Championship game at Sports Authority Field at Mile High on January 24, 2016 in Denver, Colorado.

As the Broncos’ star pass rusher learned from reading 9News.com this week, he’s gone a career-most five games without a sack dating back to the final four games of last season.

Sure, he’s getting double and triple teamed. But against a strong, agile quarterback like Prescott, Miller is the Broncos’ best chance of sacking him. Besides, now that Miller knows there’s a sack skid, he will be determined to snap it.

Cowboys right tackle La’el Collins will need help against Miller.

5. Man up

Bennie Fowler #16 celebrates a touchdown catch with offensive tackle Garett Bolles #72 of the Denver Broncos in the first quarter of the game abasing the Los Angeles Chargers at Sports Authority Field at Mile High on September 11, 2017

The Cowboys’ offensive front can’t be as good this year without Leary, but they’re still formidable with All Pro Tyron Smith and Collins at the tackles and All Pros Travis Frederick and Zack Martin on the inside. And Chaz Green is a 6-foot-5, 300-pound tackle playing left guard.

The Broncos are adjusting by activating 334-pound defensive lineman Zach Kerr and possibly newly signed 321-pound defensive tackle Ahtyba Rubin.

As for the Broncos’ offensive line, it’s going up against a Cowboys’ front that ranked No. 1 against the run last year (83.5 yards per game) and held the Giants to just 35 yards in the opener.

6. Protect the football

Kicker Brandon McManus #8 of the Denver Broncos celebrates a field goal in the third quarter of the game against the Los Angeles Chargers at Sports Authority Field at Mile High on September 11, 2017 in Denver, Colorado. 

The Broncos tried to give the game to the Chargers last week with two, fourth-quarter turnovers that turned into 14 quick points off Philip Rivers passes. The Dallas defense only registered 20 takeaways (tied for 19th) last year so there’s no reason why the Broncos’ offense can’t play a clean game.

7. Force turnovers

Ezekiel Elliott #21 of the Dallas Cowboys is tackled by B.J. Goodson #93 and Olivier Vernon #54 of the New York Giants at AT&T Stadium on September 10, 2017 in Arlington, Texas.

This will be a tall order for the Denver D because Elliott only lost one fumble last year (although he was lucky four others were recovered by his own team) and Prescott has only thrown four interceptions in 17 career games.

Still, the Broncos ranked 7th last year in forcing 27 turnovers.

8. Win special teams

Riley Dixon #9 and kicker Brandon McManus #8 of the Denver Broncos celebrate an extra point in the second quarter at Sports Authority Field at Mile High on September 11, 2017 in Denver, Colorado.

Between the nice returns of McKenzie (that set up one touchdown) and Cody Latimer last week, the superb punting of Riley Dixon and Shelby Harris’ blocked field goal, Brock Olivo’s special teams units played a huge part in the Broncos’ victory.

Dallas has a very good kicker in Dan Bailey, but an inexperienced returner in rookie Ryan Switzer.

9. Finish

Quarterback Trevor Siemian #13 of the Denver Broncos celebrates a touchdown with Garett Bolles #72 in the second quarter of the game against the Los Angeles Chargers at Sports Authority Field at Mile High on September 11, 2017 in Denver, Colorado.

It’s always something. Last year, the Broncos ranked 32nd in 2016 in first quarter points, but No. 2 in fourth quarter scoring.

In the opener of this new season, the Broncos started fast but finished poorly. Odd tendencies happen every year for every team so the Broncos will have to focus come the fourth quarter.