Mark Helfrich calls the Oregon football program "the greatest nit-pickers in the world."

That's his take on the standards the second-year head coach has to follow in the wake Chip Kelly's run in Eugene. Oregon is now defined as a disappointment after a two-loss season, something Helfrich's Ducks delivered in part because of injuries to quarterback Marcus Mariota, but also because of a defense that imploded down the stretch.

Oregon lost to Stanford, then allowed 42 points in a blowout loss at Arizona, then had to outgun rival Oregon State 36-35 a week later. On the year, the Ducks' defensive F/+ rating finished outside the top 20 (No. 22) for the first time since 2009.

Exit defensive coordinator Nick Aliotti, who retired in favor of longtime linebackers coach Don Pellum.

"As it stands right now, [the defense] is to be determined," Helfrich said at Pac 12 Media Days. "In general, I saw a lot of missed tackles, a lot of times up front where we could've done things differently. I think part of that falls to us as coaches, and part of that is execution, but that falls back on us. We're not going to dog cuss our players, because execution is coached."

"It's all of it. It's a cocktail of recruiting, player conditioning and scheme. It's not that simple to say it was just one of those things. For one guy it might be that he wasn't hearing a call, but there's so many variables other than just saying, 'Hey, we didn't stop the run in this game.'"

And now the Ducks' defense has to worry just as much about offensive tempo as the rest of the Pac-12's defenses have had to worry about Oregon's. For all of its innovation, Helfrich and his players said the focal point of the defensive scheme transition has been to hurry things up and address miscommunication of play calls.

"Basically we're streamlining across the defense," linebacker Derrick Malone said. "Being able to communicate different looks and different changes. That's really what we've been working on, is becoming a more cohesive defense in terms on communication. It's speed, doing it faster, and also the amount you're communicating."

Malone spoke to the development aspect, saying that the Ducks have placed an added emphasis on building bulk defensively -- after giving up 219 or more rushing yards four times in the regular season's final five games.

"Oh yeah, I've been eating a lot of chicken. A lot protein shakes," Malone said.

"I haven't seen official weights," Helfrich said. "But they're looking bigger."