Clearly, it was obvious that the Baltimore Ravens' ferocious pass rush was going to be hurt without hybrid linebacker Terrell Suggs on the field this year. Suggs, who suffered an Achilles tendon tear in the spring, is set to be sidelined for much of—if not the entirety of—the 2012 season.

Though we're just three games in, it's clear where the Ravens are missing Suggs' contributions the most—on first and second downs.

Last season, Suggs had 14 sacks, with five of those on first downs and four on second. So far this year, the Ravens as a team have combined for eight sacks, with only two on first and one on second downs.

R1_original First down without Suggs: Courtney Upshaw will attempt to bring the pass rush to Tom Brady.
R2_original Upshaw, lacking the speed and strength of Suggs, gets caught up with the Patriots' offensive lineman. Brady glances his way, but isn't worried and sets to pass.
R3_original Upshaw gets a bit deeper, but he cannot unlatch from his man and Brady has the easy completion.

All of those first-down sacks came on a 1st-and-10, killing opponents' momentum before it even began and forcing them to dig out of holes that they often could not escape. Second-down sacks do much of the same, especially when it results in offenses facing an oft-insurmountable 3rd-and-long. Even when Suggs' early-down pressure didn't result in a quarterback sack, it often caused incomplete passes and interceptions thanks to being forced into throwing too quickly.

This was the crux of the Ravens high-production pass rush last year, and now that they're without it, they have gone from being the fourth-best pass defense in the league last year to 28th through the first three games of this season.

R13_original First down with Suggs: Clearly, Suggs is getting ready to attack 49ers quarterback Alex Smith.
R14_original Smith tries to shake Suggs off his scent by going play-action. Suggs does pause to examine the situation.
R15_original However, before Smith can get set to throw, Suggs is aware of the fake and doesn't even concern himself with Frank Gore.
R16_original Suggs' pressure forces Smith to throw too quickly, and it's an incompletion with Gore as the target.

Albert McClellan and rookie Courtney Upshaw have taken over rotationally at the rush linebacker position that was Suggs' for last season (aside from when he was lined up as a defensive end—Pernell McPhee has taken over those snaps). So far, Upshaw and McPhee have a half-sack apiece, but beyond that, the main sack producers this season have been nose tackle Haloti Ngata (2.5) and linebacker Dannell Ellerbe (2.5). 

Without Suggs, opposing defenses aren't entirely worried about consistent, unyielding pressure coming from his side of the field. While this has opened opportunities for other members of the Ravens defense, missing Suggs has resulted in a different and less effective approach to the pass rush—blitzing.

R4_original Second down without Suggs: Paul Kruger will bring the pass rush to Brady on this play.
R5_original Again, like with Upshaw, Kruger just doesn't have the power to manhandle his blocker. Brady's not even concerned.
R6_original Like Upshaw before him, Kruger does get close in on Brady, but not early enough to force a bad throw. Brady completes for 12 yards to Rob Gronkowksi.

Opposing offenses are fairly adept at picking up on the blitzes thrown at them. There is an element of surprise, to be sure, but an unsuccessful blitz results in uncovered or single-covered receivers downfield and an opportunity to make a play if the quarterback can stay protected or get a throw out in time.

With a traditional pass rush, the Ravens didn't have to sacrifice coverage in the backfield. Now that they do, they're giving up many more pass yards. The blitz, clearly, is less effective for Baltimore than sending Suggs to repeatedly do the dirty work.

A player of Suggs' caliber obviously cannot be replaced by just any linebacker, committee of backers or anyone else. We were all well aware his absence would affect the entire Baltimore defensive production, but now that the season is underway we can see exactly how.

R7_original Terrell Suggs on second down: He's up, and he's ready to rush Brady.
R8_original Suggs does get caught up with the Patriots' offensive line, even being knocked down.
R9_original Suggs, you can barely see him, is pretty much on the ground. Play over? Brady clearly doesn't think so. Though Suggs isn't on his feet, Brady's still wary about his next move. He tries to get away.
R10_original Suggs is up, and no one is stopping him. Brady looks directly his way, a respect he didn't give the Ravens' pass rush this past Sunday.
R11_original Suggs is practically on top of Brady when he pulls his arm back to throw, hurried.
R12_original_original The result: Brady is pancaked as he throws, and it's an incompletion forcing a 3rd-and-7 in the AFC Championship game.

It's not just that Baltimore lacks a pass rush, it's that it lacks one that can hold quarterbacks at bay. Blitzing isn't what the Ravens are best at, but now they've had to adapt on the fly and thus far it's not yielding the desired results when it comes to opposing offenses keeping drives alive.

Yes, the Ravens are 2-1, but more than ever that has had to do with their offense stepping up and filling the void left by Suggs and not the rest of the defense. That first- and second-down pass rush was clearly the calling card of Baltimore's defense with Suggs in the mix, and now that he's sidelined, they need to find another way to produce drive-killing stops.