Make no mistake: Ted Cottrell is one of the brightest defensive minds in the game. He is an excellent defensive coordinator and didn't simply forget how to coach at some point during the offseason. Nonetheless, the results were too staggeringly bad to ignore any longer.
After eight weeks, the Chargers rank last in pass defense (265.1 yards per game), allowing more than 25 yards per game more than the second-worst pass defense in the AFC, the Denver Broncos. The Chargers also rank in the bottom-three in opponents' completion percentage (68.1) and passing touchdowns allowed (14).
The explanations for the drop-off extend beyond Cottrell. The biggest reason for the dip is the absence of Shawne Merriman, who accounted for nearly 40 sacks and countless rushed throws between 2005 and 2007. Without Merriman, the pass rush lost its legs and the pass rush followed suit.
The defense never recovered without its emotional leader, allowing the fifth-most points in the NFL (199). For Cottrell, scheming to play without Merriman was tantamount to a chess player attacking without his queen. Although the match goes on, sustained success is nearly impossible.
The Chargers now hope a fresh voice will bring a fresh attitude to the defense. San Diego defenders have been seen arguing with each other on the field in recent weeks, so Rivera's first task will be to get this unit on the same page.
Schematically, it's hard to imagine Rivera will be an upgrade over Cottrell. One of the reasons Rivera accepted the job as inside linebackers coach last season was he wanted more experience coaching the 3-4 scheme. He'll be learning on the job now, as the Chargers don't have the personnel to run the 4-3 defense that Rivera is most comfortable with.
However, it is likely the defense will show marked improvement under Rivera. Firstly, Rivera will provide a new voice and new direction for a defense that had grown weary of seeing the same tactics net the same results. Secondly, and more importantly, the Rivera-led defense has nowhere to go but up.
--Click here to read Ron Rivera's comments about his promotion.
--Click here to read what Norv Turner had to say about making the change.