ENGLEWOOD, Colo. --The Broncos know they'll face the Atlanta Falcons on Sunday. But they don't yet know who their starting quarterback will be.
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A look at the most important matchups that could help decide Sunday's game against the Atlanta Falcons. (Photos by AP)

Eleven touchdowns. 1,473 yards. Just two interceptions. Matt Ryan is off to a blistering start to the 2016 season and is near the top of many potential MVP lists. His return to brilliance is a big reason why the Falcons are off to a 3-1 start this season. But another player lurks near the top of the MVP watch lists, as well: Von Miller. With 5.5 sacks through four games, Miller is on pace to at least challenge the all-time sack record held by Michael Strahan. If the Falcons drop back as many times as they did against the Panthers, Miller will definitely have his chances to add to that total and maybe force a fumble or two in the process.

The biggest playmakers will line up across the line of scrimmage from each other on Sunday. Falcons wide receiver Julio Jones, who racked up 12 catches for 300 yards and a touchdown last week against the Panthers, may be the most explosive receiver in the league right now. Cornerback Aqib Talib will help slow him down. Talib has three picks in four games, including one for a touchdown. In a Broncos secondary that is dominant across the board, Talib may be the biggest playmaker. As Head Coach Gary Kubiak said at his press conference on Thursday, that knack for game-changing plays is what makes a good cornerback a great one.

The Falcons gained a three-time Pro Bowl center in free agency when Mack voided the final three years of his contract with the Cleveland Browns and signed a new five-year deal with Atlanta in March. The move reunited Mack with Falcons offensive coordinator Kyle Shanahan, whose high-powered system has powered Atlanta to a 3-1 start. Mack's impact is truly felt in the Falcons' run game, which ranks fourth in rushing yards per play and sixth in rushing yards per game. As Williams lines up over Mack, he will look to create penetration in Mack's blocks to disrupt Atlanta's line and get into the backfield. Williams already has one sack and three quarterback hits.

In his second year in Head Coach Gary Kubiak and Offensive Coordinator Rick Dennison's offense, Demaryius Thomas has looked more successful through four games. He has caught 21 passes for 332 yards and two touchdowns, in spite of hip injuries that have bothered him since the season opener. Cornerback Desmond Trufant will likely draw the assignment to guard the physically imposing Thomas, who is not afraid to use his height to his advantage over smaller corners. Though Trufant has been a tough corner to beat this year, the Falcons passing defense ranks 31st in passing yards allowed per game and 19th in passing yards allowed per play. Trufant has one interception, two passes defensed, one sack and 14 total tackles though four games.

The Falcons' third-year runing back out of Florida State has bounced back from a poor opening week performance to provide another threat for the pass-heavy Falcons. Freeman rushed for 152 yards on 14 carries in a Monday Night Football win over the Saints, and he's averaging 5.9 YPC on the season. As the Broncos look to limit the passing game, Freeman and backfield partner Tevin Coleman will be depended on to help the Falcons remain two dimensional. Broncos linebacker Brandon Marshall, who leads the team in tackles, will be among the players looking to contain Freeman and Coleman. If Marshall and Co. can limit the running game as a threat, they'll set the secondary and pass rushers up for even more success.
- SIEMIAN QUESTIONABLE FOR SUNDAY**
Trevor Siemian is still "working through soreness" in his left, non-throwing shoulder, Head Coach Gary Kubiak said after Friday's practice. But he continued to throw, and will get some more throwing in Saturday as Kubiak determines whether Siemian or rookie Paxton Lynch will start.
Kubiak said he doesn't necessarily need to warm up Siemian on Sunday to determine whether he plays, unlike with other positions.
"I don't think I need to work out a quarterback to know if he can play or not, like we do other players that run, cover and do those types of things," Kubiak said. "It's more me watching him over the next 48 hours, and seeing how he does [Saturday]."
Kubiak said he felt good about Siemian's ability to avoid contact and a hit that would exacerbate the injury.
"He's shown the ability to move and do the things he needs to do," Kubiak said. "It's really just us watching him [Saturday] and seeing what we think, and going from there."
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- THE SHORT WEEK NEXT WEEK WILL NOT FACTOR INTO THE QB DECISION**
Kubiak made it clear that the quick turnaround and trip to San Diego for a Thursday game next week will not impact this weekend's choice.
"Thursday really has nothing to do with Sunday," Kubiak said.
And that extends to three other players who are also listed as questionable: right tackle Donald Stephenson, tight end Virgil Green and safety Shiloh Keo. All are questionable for the Falcons game.
Green and Stephenson have not played since Week 2 because of calf injuries. As with Siemian, their status will be determined this weekend.
Cornerback Kayvon Webster was ruled out for Sunday; he spent Friday's practice doing rehab work following the hamstring injury he suffered last Sunday. Lorenzo Doss is expected to be active in his spot.
"Doss has really stepped up. It's time for him to contribute," Kubiak said.
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- LIKE LOOKING INTO A MIRROR**
In zone-blocking based offenses, the offense can keep the defense off-balance because runs and passes look similar at the snap. That gives the Broncos' defense an advantage most foes won't have against Atlanta's high-octane attack, because Denver's defenders saw it all summer.
"We've practiced against it. We know what to expect," inside linebacker Brandon Marshall said. "It's not too far-fetched as far as what we've been seeing [in practice]. It helps us out a lot."
"It definitely helps when you play against a team that's similar, that wants to do the same thing our offense does," added cornerback Chris Harris Jr.
But the same is also true for Atlanta's defense against the Broncos' offense. Sunday's winner may be determined by which offense can better deceive its opponent.
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- FIGURING OUT THE START**
Atlanta has jumped on its opponents early, outscoring them 31-10 in the first quarter of games this season. Its plus-21 point differential in the first quarter has helped fuel the Falcons' 3-1 start; they have a negative point differential in the second (minus-1) and fourth (minus-3) quarters.
"They're a fast-starting team," Kubiak said. "They've been jumping on some people pretty early. It's obviously important that you play well all game long, but they have been a fast-starting team."
Meanwhile, the Broncos have a minus-11 point differential in the first quarter, their worst figure for any quarter of the game. Denver has allowed 24 points in the first quarters this season, and just 40 in the final three quarters of each game.
In particular, the Broncos have had trouble with the first 15 plays, allowing 5.55 yards per play on those snaps, compared with 3.71 yards per play in the rest of the game.
"It's always tough when you go against the first 15," Marshall said.
But after that, the Broncos' defense has dominated.
"We might start off slow, but we come into halftime and we've got some adjustments, or the game has slowed down, so to speak," Marshall said. "By that time, we're killing them in that third or fourth quarters."
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- FAMILIAR FACES**
You start with the obvious connection: Falcons offensive coordinator Kyle Shanahan is the son of longtime Broncos head coach Mike Shanahan and a former member of Kubiak's staff in Houston.
"Kyle is as sharp of a guy as I have ever worked with," Kubiak said. "He's exceptional at attacking defenses and knowing what he wants to get done. We all know how he grew up and being around ball all the time. He's great with players and knows how to get guys the ball."
But Falcons defensive coordinator Richard Smith served two stints on the Broncos' staff, from 1993-96 as a special-teams coach and again from 2011-14 as the linebackers coach.
Shanahan's offense has some of the same nomenclature and concepts as the one Kubiak and Offensive Coordinator Rick Dennison guide, and Smith's teaching played a key role in the development of Broncos starting linebackers Marshall, Von Miller and Todd Davis.
"He really played a huge part in my development," Miller said. "The type of football player that I was when I first got here, he helped me become the type of player that I am today."
Through Miller, Smith's lessons continue to guide Denver's linebackers.
"I try to send those same messages, those same techniques and just those same vibes that he portrayed to me, I just try to give the same vibes to the rookies," Miller said. "I still have some of the same quotes that he used to tell me and some of the same techniques."
A history of the Broncos' series with the Falcons through photos. (photos via Denver Broncos photo archive/Eric Bakke unless noted)

Rookie RB Sammy Winder rushed for 27 yards and one touchdown.

QB John Elway threw for 291 yards and three touchdowns as the Broncos routed Atlanta.

RB Tony Dorsett rushed for 86 yards on 17 carries in the Broncos' win.

Karl Mecklenburg had one of the Broncos' three sacks on Falcons QB Steve Dils.

Broncos cornerback Jeremiah Castille (28) intercepts a pass intended for Atlanta Falcons wide receiver Stacey Bailey (82). (AP Photo/Damian Strohmeyer)

The Broncos fell behind by 11 points in the fourth quarter, but John Elway led a thrilling comeback victory beginning with a 32-yard touchdown pass to WR Anthony Miller. Elway would give the Broncos the lead on a 4-yard touchdown run, and the defense would close out the win.

RB Terrell Davis, who rushed for 79 yards on the day, added a touchdown and gave his customary Mile High Salute afterward.

WR Rod Smith caught three passes for 28 yards, including this reception where he got past linebacker Henri Crockett.

Before the game against the Falcons in the Georgia Dome, Broncos Owner Pat Bowlen met professional golfer John Daly, who had won the British Open in 1995 and the PGA Championship in 1991.

A year after winning the franchise's first Super Bowl, the Broncos faced the Falcons and former Broncos head coach Dan Reeves in an attempt to win back-to-back championships.

The Broncos broke the game open when QB John Elway found WR Rod Smith on an 80-yard touchdown in the second quarter. Smith finished the game with 152 receiving yards and one touchdown.

Elway, the Super Bowl MVP, threw for 336 yards and a touchdown, and he rushed for a score, as well.

The Broncos celebrate the defense holding on fourth down to shut down the Falcons. Denver's defense was dominant, holding QB Chris Chandler to 219 passing yards, one touchdowns and three interceptions. The Broncos also forced a fumble and sacked Chandler twice.

QB John Elway finished his career on top with back-to-back Super Bowl victories and a Super Bowl MVP.

WR Rod Smith had a dominant day with 117 receiving yards and two touchdowns.

Rookie RB Mike Anderson, who would break out with 1,487 rushing yards in his first season, burned the Falcons for 131 yards and two touchdowns on the ground.

Falcons QB Michael Vick brought a high-powered offense to Invesco Field at Mile High and carved up Denver's defense for 252 passing yards, two passing touchdowns, zero interceptions and 115 rushing yards.

In an offensive shootout, the Broncos put up big numbers but could not stop the Falcons on defense. Still, WR Rod Smith had a career-high 208 receiving yards and a touchdown. QB Jake Plummer threw for 499 yards and four touchdowns, but his three interceptions led to 17 points for Atlanta, including a pick-six.

Falcons RB Michael Turner made things difficult for the Broncos' defense, rushing for 81 yards and two touchdowns.

Tight end Daniel Graham, who caught the go-ahead touchdown from QB Jay Cutler with 5:42 left in the game, celebrated his score by dunking on the goalpost, a move since outlawed by the NFL in 2014.

In Peyton Manning's second game as a Bronco, the team struggled on the road against Atlanta. Falcons QB Matt Ryan completed 24 of 36 passes for 219 yards and two touchdowns with no interceptions. WR Roddy White had 102 receiving yards and one touchdown.

The Broncos nearly mounted a comeback late in the game on the back of RB Willis McGahee's two rushing scores, but the team could not hold Atlanta to a three-and-out to give them the ball back for a potential game-winning drive.