San Francisco 49ers: Can They Upset Peyton Manning and the 4-1 Denver Broncos?

The San Francisco 49ers take on the Denver Broncos this Sunday, and it promises to be a humongous mountain to climb for the 4-2 49ers.

The team is coming off a short week, thanks to their Monday night affair against the St. Louis Rams.  They have to travel to Sports Authority Field rather than taking on the Broncos at home.  There, they will meet the 4-1 Broncos, who have been as good as any team in the NFL this season—their only loss was a nail-biter of an overtime loss to the Seahawks in Seattle.  They are currently my pick to win the Super Bowl this year.

Billy Hurst/Associated Press

Furthermore, the 49ers are the walking wounded.  Not only will NaVorro Bowman and Aldon Smith miss the game, as expected but the 49ers defense will also practically be a B-team.  Tramaine Brock, Patrick Willis and Jimmie Ward are all expected to miss the Denver game with a variety of injuries.  On offense, Mike Iupati is still going through the NFL’s concussion protocol, and Anthony Davis’ status remains in question.

Furthermore, the crowd should be pumped for the chance to see Peyton Manning break Brett Favre’s all-time touchdown record.  Manning needs three touchdown passes to move into sole possession of first place, so it’s a question of when, rather than if, he’ll break the record. 

Manning has thrown three or more touchdowns in 88 of his 245 starts, while the 49ers have allowed three or more passing touchdowns in only five of their 54 games under Jim Harbaugh.

Add it all together and you have the toughest matchup for the 49ers this season—even tougher than the road trip to Seattle later in the year.  At least for that game, they’ll be coming in on full rest with a healthier roster.  This will be their toughest test in the regular season.

That doesn’t mean it’s an impossible mountain to climb, however.  The 49ers aren’t your average NFL team—they’re legitimate playoff contenders who shouldn’t be counted out of any game anywhere in the league.  So, this is a situation where 49ers fans should probably be prepared to lose a game, but they shouldn't consider it a foregone conclusion—it’s unlikely the 49ers pull this one off, but it's not impossible.

So, how can the tired, poor, huddled mass that is the San Francisco 49ers at the moment pull off the upset in Denver?  Denver’s a very solid overall team, but that doesn’t mean there aren’t cracks that can be exploited.  There is one aspect of the game where I think the 49ers might actually have the advantage.

JACK DEMPSEY/Associated Press

The greatness of Peyton Manning tends to hide one crucial fact—Denver’s offensive line isn’t very good, at least for a Super Bowl-caliber team.  With the exception of left guard Orlando Franklin, the entire offensive line has negative grades from Pro Football Focus (subscription required).

Louis Vasquez and Chris Clark, the right side of Denver’s offensive line, have a mixed grade—they’re both very good in pass protection, but they have been liabilities in the run game.  Center Manuel Ramirez and left tackle Ryan Clady, on the other hand, have put up negative grades in both pass and run blocking.  They have not looked good this season.

The offensive line, combined, has given up four sacks, nine quarterback hits and 24 quarterback hurries in only five games—and that’s with Manning making adjustments and reading defenses as well as he does.  In addition, Football Outsiders ranks Denver 25th in terms of run blocking in general.

Is this a small sample size or indications of an actual weakness to exploit? That’s tough to tell; the Broncos as a unit were better last season.  At the very least, however, they’ve been subpar up to this point in 2014, so attacking them until they prove they can hold up protection-wise is probably the best plan.

Attacking Clady, who still isn’t back to full speed from the Lisfranc injury he suffered last season, is probably the 49ers’ best bet to attack.  He really struggled last week against Jason Babin and the right side of the New York Jets defense, as he allowed three hurries and a hit, per PFF. 

The left side of the line in general seems like a good target, so the 49ers will need Ahmad Brooks to have a big game at the right linebacker spot.  As the last healthy stud linebacker, Brooks will need to carry a decent chunk of the defense this week.

John Froschauer/Associated Press

Historically, Manning has been good against the blitz, but that hasn’t been the case so far this season.

According to PFF’s charting stats (subscription required), Manning’s only 31-of-52 for 360 yards and a sack when facing the blitz.  He still completes passes, but they’re frequently short dumpoffs that don’t get very many yards.  He’s even worse when the pressure comes without a blitz—18 of 41 for 232 yards and five sacks.

Getting pressure without devoting extra men to the attack will be key, so the 49ers need to vary their defensive looks up—give Manning something he hasn’t seen on tape before.  Hitting Manning breaks up his otherworldly efficiency, and the 49ers will have to do that to stand a chance in this game.

The 49ers started off slowly in the quarterback hits department, but they have picked it up since then:

Game	Sacks	Hits	Hurries
@Dallas	3	1	6
v.Chicago	1	1	8
@Arizona	0	2	6
v.Philadelphia	1	5	10
v.Kansas City	0	2	10
@St. Louis	5	1	25

Obviously, it’s a lot easier to get pressure against Austin Davis than it is to get that pressure against Manning, but the team is trending up in general.  The 49ers need to harass Manning to have any chance in this game—if the combined sacks, hits and hurries aren’t at least in the 10-plus range, I don’t think the 49ers will come out on top in this one.

In the one game Denver lost, Seattle found their way into the backfield early and often.  Manning was hit eight times and hurried another 11, as Michael Bennett and O’Brien Schofield came crashing in repeatedly against Ryan Clady. That’s what the 49ers need to emulate if they’re going to come out on top in this one.

Pressure isn’t a guaranteed victory—Manning and that passing offense are good enough to come back from nearly any hole you put them in.  However, it is a necessary component for the 49ers to pull off an upset this Sunday.

Bryan Knowles is a featured columnist for Bleacher Report, covering the San Francisco 49ers.  Follow him @BryKno on Twitter.