Why Zach Arnett could be a fit for USC's next defensive coordinator

USC finally pulled the trigger to fire Alex Grinch this past week and now finds itself in search of a new defensive coordinator for next season. The Trojans defense has been abysmal for the past two seasons and so far this year ranks 124th out of 133 FBS teams with 34.5 points allowed per game.

Now the speculation can begin for who will replace Grinch in that role, and On3‘s Andy Staples already has an idea. On his Tuesday podcast with former Oregon and NFL offensive lineman Geoff Schwartz as his guest, Staples suggested Mississippi State coach Zach Arnett.

Arnett’s first season as the Bulldogs coach hasn’t gone well as he has led the team to a 4-5 (1-5 SEC) record. There’s been some rumors he could be fired at the end of the year, and if that’s the case, Staples sees him as a good fit.

“I realize he’s the head coach at Mississippi State right now and you’re probably thinking, ‘why?'” Staples explained. “Well, because he’s probably gonna get fired. He’s got a $4.5 million buyout with an offset. He’s a Rocky Long guy. Knows Southern California. Runs a 3-3-5, which is a little bit different. Gives you a little bit more to think about during the week of practice.”

As Staples mentioned, Arnett got his start in coaching as a graduate assistant under Long at San Diego State in 2011. He later moved his way up the ladder to become linebackers coach and eventually defensive coordinator, helping the Aztecs to rank second in points allowed (12.7) in 2019.

That caught the attention of Mike Leach, who hired Arnett to be his defensive coordinator when he took over at Mississippi State in 2020. Leach’s tragic passing in 2022 allowed Arnett to take over as the head coach.

Schwartz believes that Arnett’s experience working under Leach would prepare him to complement a Lincoln Riley offense, as Riley cut his teeth under Leach as an assistant at Texas Tech from 2003-09.

“I think the Leach thing is important, knowing the sort of offense that you’re getting yourself into having to play against in practice and knowing you’re not gonna have to spend as much time hitting,” Schwartz said. “Even though Mike Leach was sort of old school in that I think he did like to hit a little bit. The 3-3-5 is not run a lot. TCU does it for sure. But ACC, Big Ten, Pac-12, no one’s running 3-3-5. It’s a Big 12 thing more than anything else.”

Schwartz believes that the unique 3-3-5 system that Arnett runs could cause fits because of how rare it is to play a team that uses it. Mississippi State ranked fifth in the SEC in total defense each of the three seasons that Arnett worked under Leach.

However, more than the system, he believes that the Trojans have to get bigger athletes on the defensive line. Otherwise, with them moving to the Big Ten next year, he could see them getting pushed around up front.

“As an offensive lineman, I sort of hated playing those teams that ran a version of that,” he said. “Because the fits are hard to get to. I think that problem is you just become a little small. That’s sort of the issue in that situation. But look, anything would be better at USC. The players are OK if you just play straight up, but you’re too small to play straight up.

“Bear Alexander is 300 pounds. OK, good. The other defensive tackles are 275. I’m not sure if you watched Oregon’s offensive line, but if you’re 275 playing three-technique, you are being ejected off the ball away from the run. So they’ve just gotta get bigger first and foremost. Anything would be great. Just get bigger players.”

Ultimately, we’ll have to wait and see whom USC targets for the open defensive coordinator job. However, the case for Arnett is certainly an interesting one given how he would fit the scheme.