Last season, two-thirds of the Pac-12’s starting quarterbacks were brand new.

Some were known quantities, like Oklahoma-wunderkind-freshman-turned-USC-Heisman-winner Caleb Williams and Arizona then 1st-year starter Jayden de Laura, who arrived in Tucson fresh off Pac-12 freshman of the year honors for Washington State in 2021.

Others were complete guesses, like Arizona State’s Emory Jones and Oregon’s Bo Nix, a pair of SEC transfers who delivered varying results. Jones flamed out for the Sun Devils after arriving from Florida while Nix flew sky-high for the Ducks after a middling Auburn career.

You had leaders bumping up a level, like Wazzu’s Cameron Ward, who took the leap from Incarnate Word of the Football Championship Subdivision, and some arguably moving down, namely Cal’s Jack Plummer, who’d spent 4 seasons with the Big Ten’s Purdue Boilermakers.

And then there was Michael Penix Jr.

The former Indiana starter arrived in Seattle last year as Kalen DeBoer’s first reclamation project. They’d known each other well, with DeBoer serving as Penix’s offensive coordinator and quarterbacks coach with the Hoosiers for one season in 2019. That just so happened to be Penix’s best season in an Indiana uniform, as he completed 68.8 percent of his 160 pass attempts (110 completions), while averaging 8.7 yards per throw. He had just 10 touchdowns but also just 4 interceptions, finishing with a passer rating of 157.6.

Then came a significant regression, as injuries and inefficiency got the better of him. Penix completed just 56.4 percent of his passes in 2020 with DeBoer off at Fresno State as the Bulldogs head coach, and just 53.7 percent in 2021, when he finished with a paltry 101.9 rating and 7 interceptions with just 4 scores.

His performance in 2021 was so bad that his arrival in Washington last year barely raised an eyebrow. He would still have to beat out incumbent starter Dylan Morris and heralded prospect Sam Huard. When he did in fact seize the position, expectations were low, seeing as the Huskies were coming off a 4-8 campaign and under the guidance of a new head coach.

We all know what happened next, of course. Penix had an otherworldly season, leading the country in passing yardage per game while finishing with one of the best stat lines in college football — 362-of-554 passing (65.3 percent) for 4,641 yards and 31 touchdowns with 8 interceptions. He had 300-plus passing yards in 10 games, 400 in 3 and hit the absurd 500-yard mark with a 36-of-44, 516-yard, 4-touchdown, zero-interception performance in a 49-39 win over Arizona.

Ultimately, Penix put together one of the finest seasons by a Pac-12 quarterback in the history of the league.

Now he’s back in the saddle in Seattle, leaving room for the next surprising transfer QB to take the league by storm.

Who will it be? Here’s a look at the top contenders …

DJ Uiagalelei, Oregon State

Previous school: Clemson

If any incoming Pac-12 quarterback seems poised for a Penix-like rebirth, it is the former 5-star recruit for the Tigers and the once heir-apparent to the great Trevor Lawrence. Uiagalelei never quite lived up to the hype at Clemson, but he showed flashes of the talent that made him among the top high school recruits in his class. Can Jonathan Smith tap into the prodigious talent? That’s the biggest question going into what should be a huge year in Corvallis. Despite a 9-to-10 interception ratio and a 108.7 passer rating as a sophomore in 2021, Uiagalelei led Clemson to a 10-3 record. He was better last year, leading the Tigers to a 10-2 record after throwing for 2,521 yards and 22 scores, but he still hasn’t reached the peaks that people projected for him years ago. If he beats out Ben Gulbranson and Aiden Chiles for the starting gig, Uiagalelei could take off under Smith’s tutelage.

Shedeur Sanders, Colorado

Previous school: Jackson State

Coming off back-to-back ultra-productive seasons, Sanders wasn’t exactly on the trash heap like Penix, as he combined for nearly 7,000 yards and 70 touchdowns in 2 years with Jackson State. But moving from an HBCU school, no matter how talented, to the Pac-12 is not an easy proposition. Sanders should thrive under new offensive coordinator Sean Lewis, and if Sanders can indeed join his father in leading the Buffaloes to instant success, he’ll be the talk of college football.

Drew Pyne, Arizona State

Previous school: Notre Dame

The first of two straight Sun Devils on this list, Pyne had a terrific season for Notre Dame last year in relief of starter Tyler Buchner. Pyne completed 65 percent of his passes for 2,021 yards and 22 touchdowns with just 6 interceptions. More importantly, he prevented the wheels from falling off after a poor start and Buchner’s injury threatened to derail Notre Dame’s season. If Pyne emerges from a crowded QB competition, he might thrive under Kenny Dillingham.

Jacob Conover, Arizona State

Previous school: BYU

Then again, it could be Conover who makes the most of his hometown return. One of the most prolific passers in Arizona history, Conover led Chandler High School to three consecutive state 6A titles after throwing for more than 10,000 yards in high school with 102 touchdowns. He didn’t play much with the Cougars, but you can’t ignore the untapped talent in the former 4-stars arm. If Pyne doesn’t upend Trenton Bourguet and fend off Jaden Rashada — it could be Conover who settles in.

Sam Jackson IV, Cal

Previous school: TCU

Like Conover, Jackson did not see much time at his first collegiate stop. Unlike Conover, he also played sparingly in high school, playing quarterback for just one year, in 2019. He’s expected to become Cal’s starter, but expectations are light after he played in just 7 games as a 2021 true freshman and 2022 redshirt freshman, when he completed all 6 of his pass attempts for 140 yards. Given Cal’s anticipated struggles on offense, it’s hard to imagine Jackson filling Penix’s shoes.

Collin Schlee, UCLA

Previous school: Kent State

Then again, I wouldn’t stack my chips behind Schlee, either. Like Pyne and Conover, Schlee enters a crowded QB room that includes UCLA’s 2022 backup quarterback, Ethan Garbers, as well as fabulous freshman Dante Moore, who is expected to take the reins early. If for any reason Moore isn’t ready, Schlee’s starting experience for the Golden Flashes might pay off. Last year, he completed 157-of-266 passes for 2,109 yards and 13 touchdowns with 5 interceptions.