We should have seen this loss coming.
Okay, maybe not.
Shockers happen almost every week, but they don't usually happen to the New England Patriots at Gillette Stadium.
In fact, they've never happened to the Patriots in a home opener at Gillette Stadium.
This wasn't your typical Patriots game. The defense held its ground, and the offense failed to produce. The Arizona Cardinals deserve all the credit in the world. Their defense shut down a Patriots offense that many considered to be a juggernaut, and an offense that may still prove to be a juggerrnaut in time.
But for an upset like this to happen, there needs to be a fair share of miscues. So what happened?
Let's just get Aaron Hernandez's injury out of the way. The long-term effect may be felt in time (depending on the severity, but it didn't look good), but the short-term effect was obvious. The Patriots failed to find any rhythm offensively, settling for four field goals through the first 57 minutes of play.
Hernandez was primed to become one of Brady's favorite targets this year; the offense has been predicated on those two tight ends for the past two years. The Patriots may have to do some soul-searching after spending over 80 percent of their snaps in two-tight end sets in 2011 (per ESPN).
The primary problem, without question, was the offensive line.
Okay, maybe everyone.
The offense had a hard time executing as a whole, and the special teams miscues played a huge role as well, but for anyone who watched the preseason, there was nothing shocking about the Cardinals' ability to get pressure on quarterback Tom Brady. They brought him down four times and hit him another six times.
The Cardinals are a heavy blitz team, sending extra men after the quarterback 275 out of 647 snaps (42.5 percent) in 2011, and 23 out of 43 snaps (53.5 percent) in Week 1 against the Seattle Seahawks. They brought an exotic blitz package to Gillette Stadium that featured a heavy interior rush.
They attacked up the middle, a wise move considering that the Patriots are still dealing with the absence of guard Brian Waters, who has yet to report to the team. Add Dan Connolly to that—he was held out of action with concussion symptoms—and it doesn't take a genius to figure out why they targeted third-string guard Donald Thomas.
Hernandez may have otherwise been one of the team's blitz-beaters in the contest, if the Cardinals were to have continued blitzing linebackers.
The Patriots running game, which was dominant in the team's Week 1 win over the Tennessee Titans, was nearly nonexistent this week with 90 yards on 28 carries (3.2 YPA). The Patriots were consistently in bad second- and third-down situations, both as a result of their inability to run the ball as well as their inefficient play in the passing game.
Connolly's return will bring some stability back, but without Hernandez, the Patriots may have an even bigger shake-up on their hands.
None of this even takes into account the special teams miscues—a blocked punt in the third quarter, and the death knell that was kicker Stephen Gostkowski's shanked field goal with one second on the clock.
'They’re a very good special teams unit that we just have to worry about every time they come out on the field. They block a lot of kicks. Every play is a potential game-changing play on special teams. This will be a huge challenge for us in the kicking game—protecting the kickers and covering the kicks.'
There's enough blame to go around, but lost in all of this is the incredible performance by both the Patriots and Cardinals defenses. The Patriots offense had their share of miscues, but the Cardinals got bigger plays, and the biggest play: an interception. Those are often the swing plays that can change a game, and when it happens on the first play from scrimmage, it's never a good omen.
Anyone else remember Super Bowl XLVI?
Erik Frenz is the AFC East lead blogger for Bleacher Report. Be sure to follow Erik on Twitter and "like" the AFC East blog on Facebook to keep up with all the updates. Unless specified otherwise, all quotes are obtained firsthand.