EUGENE — Much has been made this week about how new Arizona football coach Rich Rodriguez pioneered the up-tempo, no-huddle offense, and how Oregon coach Chip Kelly has taken the concept and run with it, so to speak.

So while most eyes are unblinkingly watching the two hyper-drive offenses, it may be the defenses that determine the outcome when the No. 22 Wildcats visit the No. 3 Ducks tonight at Autzen Stadium.

“Everybody’s got their work cut out for them," Oregon safety Brian Jackson observed.

Both defenses have plenty of numbers to ponder right now.

Arizona is averaging 46.3 points per game, 12th in the nation, compared with Oregon’s 54 points, fifth nationally. The Wildcats average 604.7 yards in total offense per game, fourth nationally, while the Ducks average 596.3 yards for seventh.

The Wildcats lead the nation with 108 first downs through three games, while Oregon is sixth with 89.

“They are always exciting to watch on TV because of the type of offense they run, but their team can be beat," Arizona cornerback Jonathan McKnight said. “We just have to play really hard against them."

The Wildcats have introduced a new 3-3-5 defense, which has held their opponents to an average of 382 yards in total offense and 18.3 points.

Arizona opened Rodriguez’s tenure with a victory over Toledo before upsetting then-No. 18 Oklahoma State 59-38 in its second game. Last weekend, in a 56-0 win over South Carolina State, the Wildcats ran a school-record 102 offensive plays.

“I’m not really worried about whether we’re ranked or not," Rodriguez said. “I’m worried about how are we preparing and how we are working. ... Are we doing the things we are supposed to? Are we preparing the right way? Whether we won the last three games or lost the last three games, those kinds of things are never compromised. We are keeping the main thing the main thing."

Oregon runs a hybrid 3-4 defense under longtime defensive coordinator Nick Aliotti. Because the Ducks’ offense is so quick, the defense is a well-conditioned unit and adept at rotating players in and out. This season, Oregon is holding opponents to averages of 357 yards of total offense and 24 points.

“We’re just going to have to be very disciplined as a defense and have our eyes right," Oregon defensive end Dion Jordan said. “And just give a tremendous effort as far as getting to the ball and making plays."

Arizona’s offense is paced by quarterback Matt Scott.

After spending two seasons behind standout Nick Foles, the fifth-year senior has taken command of Rodriguez’s read-option offense, ranking fourth nationally with a total of 395 yards per game. Scott is the Pac-12’s leading passer, with 995 yards passing, and is eighth in rushing with 190 yards.

“We know he can pull the ball and run, just like the quarterbacks that play here," said Oregon defensive tackle Isaac Remington. “We just have to stay disciplined."

On their side, the Ducks have redshirt freshman quarterback Marcus Mariota. In his first three career starts, Mariota has helped lead the Ducks to victories over Arkansas State, Fresno State and Tennessee Tech. In a 63-14 win over lower-division Tennessee Tech last weekend, Mariota completed 21 of 28 passes for 308 yards and four touchdowns. It was the first time in school history that a freshman quarterback had passed for more than 300 yards.

Mariota has thrown eight touchdown passes this season with just one interception, and he is completing more than 75 percent of his passes. He is ranked 10th in the nation and first in the Pac-12 with a quarterback efficiency rating of 180.54.

“He’s a perfect fit for their system but he could play any system," Rodriguez said of Mariota. “He’s fast, but he’s got a live arm, he sees the field. For a young guy, a redshirt freshman, he’s playing as well as any quarterback in the country. I’m very impressed."

Before this season, Arizona had not been ranked in the AP Top 25 since November 2010, when the No. 20 Wildcats were knocked out with a 48-29 loss to the then-No. 1 Ducks.

Last season, Oregon defeated Arizona 56-31 in Tucson.