USC coach Lincoln Riley thought that making a defensive coordinator change now -- with two games remaining, leading into the Trojans' toughest test of the season on the road at No. 6-ranked Oregon -- would give the team a chance to salvage a strong finish.

As he's reiterated many times, USC still has major stakes attached to its trip to Eugene, Oregon, as the Trojans (7-3, 5-2 Pac-12) can play their way into the Pac-12 championship game with an upset of the Ducks (8-1, 5-1) and a win over UCLA next week.

There's just the whole matter of that 120th-ranked USC defense (out of 130 FBS teams) that gives up 436 yards and 34.5 points (121st) per game and now has to slow down the highest-scoring team in the country in Oregon (47.4 PPG) on the road in a raucous Autzen Stadium.

With interim co-defensive coordinators trying to make changes to a fatally-flawed defense on the fly in less than a week.

That's all.

RELATED: TrojanSports.com Roundtable: Staff predictions and perspective for USC-Oregon | PODCAST: Covering the Alex Grinch aftermath with Antonio Morales and Max Browne | USC's interim co-DCs talk challenge ahead | USC's defensive players look to rally after Grinch firing

"You’re not going to reinvent the wheel in the matter of one week," said linebackers coach Brian Odom, one of the newly-minted co-DCs. "But the goal of this week obviously is to win the game. To be able to put our guys in the situation to play fast, for things to be simple for them and go make a difference when they’re on the field."

How much can Odom and fellow co-DC, defensive line coach Shaun Nua really change in a week?

"That’s the million-dollar question right now. When we go in and visit, what can we change to help the guys execute at a high level and what can we not? We’ll find out Saturday," Nua said.

Yes, they sure will.

These are two programs going two different directions under second-year coaches, as Dan Lanning has the Ducks surging with their only loss coming 36-33 on the road at now-No. 5 Washington. Since then, Oregon has won its last three games -- against Washington State, Utah and Cal -- by an average margin of 29 points, including a 35-6 domination of the Utes and a 63-19 drubbing of the Golden Bears.

USC has lost three of its last four games, including to Utah, with the lone win in that stretch coming 50-49 to Cal.

Lanning and defensive coordinator Tosh Lupoi fixed many of their defensive issues from last season, when the Ducks ranked a middling 71st in total defense. This year, they're 18th nationally (301.7 YPG) and 10th in scoring defense (16.0 PPG allowed) and seemingly gaining momentum.

The Trojans, meanwhile, keep getting worse somehow.

Over the last six games, USC has given up 44.2 PPG and 483.7 YPG, including 572 yards (316 on the ground) to Washington last week.

"It's just all about being optimistic, knowing the guys that you're around. Just because you've had a couple rough weeks doesn't necessarily mean everything's going wrong," USC rush end Jamil Muhammad said.

It sure seems like it has been -- after all, defensive coordinator Alex Grinch didn't survive the season and Odom and Nua are now trying to patch things together on the fly with two games left.

But, hey, college football is unpredictable.

"We still have a lot to play for, we still have a really cool opportunity in front of us," Riley emphasized this week.

Let's take a closer look at the matchup heading into kickoff Saturday night at 7:30 p.m. PT (on FOX) ...

Who | USC (7-3, 5-2) at No. 6-ranked Oregon (8-1, 5-1)

When | 7:30 p.m. PT Saturday

Where | Autzen Stadium, Eugene, Oregon

TV | FOX with Tim Brando, Spencer Tillman and Josh Sims

Radio | 790 AM KABC

Spread | Oregon -16

Over/under | 77

Series history | USC leads 39-22-2 (counting one win that was officially vacated) and is 14-13-1 in Eugene. Oregon won the most recent meeting, 31-24, in Los Angeles in the 2020 Pac-12 championship game.

Familiar faces | Former USC WR Gary Bryant Jr. is in his first season with Oregon, totaling 20 catches for 265 yards and 2 TDs ... USC WR Kyron Hudson's brother is Oregon DL Keyon Ware-Hudson ... USC defensive graduate assistant Peyton Pelluer's brother-in-law is Oregon’s defensive coordinator Tosh Lupoi.

Oregon quarterback Bo Nix is second in the latest Heisman Trophy odds (+200) behind Washington QB Michael Penix Jr., whom USC faced last week. Nix is a much different player, though. He is completing 78.1 percent of his passes, which would break the NCAA single-season record (Mac Jones, 77.4 in 2020) if it holds. He's passed for 2,723 yards, 25 touchdowns and 2 interceptions and rushed for 5 scores. Nix hasn't been the same dual-threat QB he was before his late-season ankle injury last year (he had 510 yards and 14 touchdowns rushing last season), but he's remained every bit as effective a leader of the Ducks' high-scoring offense.

What's perhaps most impressive about what Oregon has done offensively this year is that it had to replace offensive coordinator Kenny Dillingham (now the head coach at Arizona State), bringing in Will Stein from UTSA. It also lost four starting offensive linemen and its OL coach and yet remains one of the best units in the country, allowing the fewest sacks nationally (just 4 all season). Right tackle Ajani Cornelius, a transfer from Rhode Island in the offseason, has not allowed a sack all season, while young left tackle Josh Conerly Jr. (a former to USC target) has allowed just 1 in his first season as a starter.

The Ducks are just as good at run blocking too, clearing the way for two of the most efficient running backs in the country in Bucky Irving (821 rushing yards, 9 TDs, 6.9 yards per carry) and Jordan James (545 yards, 9 TDs, 7.8 YPC). Oregon has rushed for over 200 yards in six of nine games this season.

As for Nix's top aerial targets, junior Troy Franklin has 58 catches for 946 yards and 10 TDs and is chasing Oregon single-season receiving records. Tez Johnson, Nix's adopted brother, has 46 catches for 599 yards and 6 TDS, and tight end Terrance Ferguson has 27 catches for 287 yards and 2 TDs.

"It's a good football team. They've gotten some momentum here this part of the year. They've obviously led by quarterback. Obviously, Bo's played at a high level for them," USC coach Lincoln Riley said. "... They've got some really good skill sets around him, a couple of really good backs, a couple really good receivers and have done a nice job offensively. ...

"They do a good job using tempo, using several different run schemes to get those [running backs] the ball. They're different, they've got different skill sets, but they're both explosive players. They've both been very productive. They've both break a lot of tackles, especially Irving. I mean, he's a guy that you got to do a good job really getting him to the ground, other people getting to the party. He's got great contact balance and a really good feel for what they're doing schematically. So yeah, like I said, they've got good players, a good scheme, a good leader there in Bo, who kind of leads the thing and certainly have made life difficult for the opposing defenses."

The growth of Oregon's defense under head coach Dan Lanning, who won a national championship as the defensive coordinator at Georgia, and DC Tosh Lupoi is what has truly transformed the Ducks into a national title contender.

They don't have one dominant star defensive player but instead a cohesive unit that plays well together and is more disciplined than a year ago.

Safety Evan Williams, a transfer from Fresno State, leads the team with 53 tackles, 4 tackles for loss and 3.5 sacks.

Ole Miss transfer Tysheem Johnson has been another key addition in the secondary, racking up 47 tackles, 2 interceptions and 4 pass breakups.

Linebacker Jeffrey Bassa is the leader in the middle of the defense with 41 tackles, 2.5 tackles for loss and an INT.

And Brandon Dorlus (5.5 TFL, 4 sacks, 6 pass breakups) and South Carolina transfer Jordan Burch (7 TFL, 3 sacks) lead the pass rush.

The Ducks have held six of their nine opponents under 300 yards, including the last two games limiting Utah to 241 yards and Cal to 286.

"Defensively, they're playing well, certainly are. I mean, they've got some really talented players at all three levels of the defense and have done a nice job. So yeah, complete team, really good football team," Riley said.

Oregon's Jordan James (7.79) and USC's MarShawn Lloyd (7.74) rank 1-2 among FBS running backs in yards per carry.

Lloyd missed USC's last game, but Riley said on Thursday the running back is expected to "be available" Saturday.

Certainly, the key for USC is containing, limiting or at least slowing down Oregon's rushing attack.

The Trojans just let a Washington team that doesn't run the ball particularly well or much -- usually -- rumble for 316 yards. That, after giving up 247 rushing yards to Utah and 235 to Cal in the weeks prior.

If the Trojans can't find answers in their run defense, this will be another long day for the unit.