How good the Broncos will be with Peyton Manning at QB should be evident Sunday when Denver hosts the Steelers. (Getty Images)

Broncos vs. Steelers -- Week 1

Where: Sports Authority Field at Mile High, Denver (turf, outdoors)

When: Sunday, 8:20 p.m. ET (NBC)

Spread: Broncos by 2

Forecast: Clear skies; projected kickoff temperature: 79

2011 records: Broncos (8-8); Steelers (12-4)

Past results: Two most recent meetings -- Jan. 8, 2012 (wild-card playoff): Broncos 29, Steelers 23 (OT); Nov. 9, 2009: Steelers 28, Broncos 10. Series record: Broncos hold a 13-7-1 edge.

What matters: Even if the Pittsburgh Steelers must do without LB James Harrison and RB Rashard Mendenhall, both of whom have missed practice with injuries, they're still the same Steelers. But the Denver Broncos scarcely resemble what they were in January -- particularly on offense, where Peyton Manning's arrival has heralded a 180-degree turn in offensive emphasis. Last year, the Broncos upset the Steelers by supplementing a run-first mindset with occasional deep shots from Tim Tebow. Look for much more short-to-intermediate passing to an array of targets Sunday as Manning tries to keep Pittsburgh off-balance.

Who matters: Rookie DL Derek Wolfe will swing inside to DT from DE on pass-rush downs, and he offers something the Broncos didn't have: a 300-pounder with pass-rush skills who might be able to bring down Pittsburgh QB Ben Roethlisberger without help if he can capitalize on the extra attention given to edge rushers Von Miller and Elvis Dumervil. WR Demaryius Thomas exploited a mismatch against CB Ike Taylor and FS Ryan Mundy in last year's playoffs and could be an even bigger threat with Manning, rather than Tebow, pulling the trigger. And no matter who runs the ball for Pittsburgh, MLB Joe Mays must avoid the missed tackles that plagued his run defense last year -- especially since he now becomes an every-down linebacker with WLB D.J. Williams suspended.

Key matchups: Although Steelers WR Mike Wallace missed the preseason because of a contract holdout, he remains their most potent downfield threat. Pittsburgh will move Wallace around to try and force one-on-one matchups that don't involve perennial Pro Bowler Champ Bailey, so the work of CB Tracy Porter and nickelback Chris Harris will be equally crucial to containing Wallace, who caught just three of 10 passes thrown in his direction during their wild-card game eight months ago.

Injuries of note: RG Chris Kuper will miss this game and perhaps the next two as he recovers from a fractured forearm suffered in practice Aug. 14. Manny Ramirez, a former Lions starter who hasn't taken a regular-season offensive snap since 2009, will take his place.

Inside stuff: Fill-in RG Manny Ramirez hasn't started since he was with the Lions in 2009, but actually spent more practice time blocking for Manning on the first-team offensive line this year than Kuper. He held up well during the preseason, but the Steelers will try to test him with blitzes up the middle early and often. If Harrison doesn't play, the Steelers could try compensating for weakened edge rushing with even more blitzes from their inside linebackers and safeties, putting a further burden on Ramirez, C J.D. Walton and LG Zane Beadles.

Connections: Broncos WR Andre Caldwell and Steelers LB Brandon Johnson played together in Cincinnati from 2008-11.

Stat you should know: The Broncos had won 11 consecutive home openers before last year's 23-20 loss to Oakland in John Fox's first game as Denver's head coach. Fox is 4-6 in season openers, including three losses in a row.

Record watch: Manning is one touchdown from the 400th of his career and needs 22 to move past Dan Marino for second place all-time.

Bulletin board quote: "(Rashard) Mendenhall, he's not a game-changer like that in my eyes. All the tailbacks they have are solid, overall as a group. We've just got to get them down and gang-tackle them. Mendenhall's a big back, but at the same time, we've still got to ground and pound and get them down, too." -- DT Kevin Vickerson

Looking ahead: This might be the most winnable game of the Broncos' first three. A Week 2 Monday night trip to Atlanta will be no picnic, and the Texans' multi-faceted offense in Week 3 is the type that has given Denver's defense fits in recent years.

Prediction: Broncos 31, Steelers 23