Oregon coach Mario Cristobal is thinking about the unthinkable.

If Justin Herbert were to get injured again this fall, the Ducks need to have a backup quarterback who is prepared to keep the ship afloat in the rough Pac-12 seas.

The Willie Taggart era got off to a 4-1 start with Herbert taking the snaps, but Oregon went 1-4 while the 6-foot-6, 231-pound starter was mending a fractured collarbone.

Braxton Burmeister, who completed 57.1 percent of his passes for 330 yards, two touchdowns and six interceptions in his five starts last season, did his best to learn from the painful trial by fire.

The sophomore was 7-of-12 passing for 64 yards with one touchdown and no interceptions during Saturday’s spring game.

True freshman Tyler Shough, who could still be in high school preparing for prom, threw a touchdown pass in his first attempt at Autzen Stadium. The 6-foot-5, 202-pound prospect from Chandler, Ariz., finished 5-of-8 passing for 103 yards and two touchdowns.

“I know it was tough when Justin went down last year, but we’ve got to do a better job as coaches,” Cristobal said after completing his first spring as the program’s CEO. “You have what you have, and when a guy goes down, I know it’s hard. We see it in the NFL and college football, and I totally get it. But we have to do a better job of having a plan.”

The Ducks, who improved from a 4-8 finish in Mark Helfrich’s final season to 7-5 under Taggart, have big plans this season with a healthy Herbert entering his third year as a starter.

Oregon averaged 52.1 points per game in the seven games Herbert started during the 2017 regular season and 15.0 points with Burmeister at the controls.

But during the loss to Boise State in the Las Vegas Bowl, Cristobal’s debut as Oregon’s coach and Marcus Arroyo’s debut as the play-caller, Herbert was intercepted twice and sacked four times.

Herbert threw the only interception in the spring game, which was returned by linebacker Kaulana Apelu for a 100-yard touchdown.

Perhaps the gap between Herbert and his young backups isn’t as wide as it was last season.

“They’ve got the right mentality, they’re competing and they know it cannot be handed to them,” Cristobal said of the competition between Burmeister and Shough. “The best part about their approach, they haven’t just sat back and said, ‘OK, well Justin’s the guy, let’s go compete for number two.’

“It’s never been mentioned, it’s never been brought up. They have to be the best player they can possibly be. That’s the only way we’re going to be able to continually be successful, because injuries are going to happen. We can never, ever enter a panic mode when a player goes down, regardless of how good that player is.”

Herbert, a first-team academic all-American, has a chance to be as successful on the field as he has been in the classroom at Oregon. The former Sheldon High standout is carrying a 4.0 grade-point average in biology.

In 17 games playing for three head coaches, Herbert has completed 65 percent of his passes for 3,919 yards with 34 touchdowns and nine interceptions. Cristobal wants his quarterback to play at a championship level as an upperclassman.

“He has to get better. For us to sit back and tell him, ‘Hey, you’re doing great, we’re good,’ would be the biggest injustice we could do to Justin Herbert,” Cristobal said. “We have to find ways to challenge him, make him better, put him in difficult situations. Because teams are going to do that. If you want to attack Oregon, how would you attack them defensively? You’d make sure that you put a lot of pressure on No. 10 and make him uncomfortable.

“So we have to continue to challenge him to get every single position on the field, he must know it inside and out, so he can own the entire defensive playbook and really have complete control of it.”

Oregon’s offense returns a veteran offensive line, fifth-year senior Tony Brooks-James at running back and familiar targets for Herbert at wide receiver (Dillon Mitchell, Brenden Schooler, Johnny Johnson) and tight end (Jacob Breeland, Cam McCormick).

“I believe if me and Justin stay healthy it could be a lot of special things that go on,” said Mitchell who caught four touchdown passes last season and led the team in receptions (42) and receiving yards (517).

Several young skill-position players made a splash during the spring game.

Redshirt freshman wide receiver Daewood Davis had three catches for 75 yards and two touchdowns. Two freshman running backs, CJ Verdell (two 5-yard rushing touchdowns) and Cyrus Habibi-Likio (29-yard touchdown reception), also got into the end zone.

“They all put down what coach needed to see and displayed their talents, which everyone can see,” Brooks-James said. “I was very proud of them and excited and happy for them. I just hope they keep it up and carry it into the season.”

While the coaches and players expressed confidence in Burmeister and Shough, the goal for Cristobal’s first season is to stick with Plan A.

That’s why members of the defense opted not to take Herbert out with a block as he chased Apelu down the field following his red-zone turnover.

“Nobody can touch Justin,” senior safety Ugochukwu Amadi said. “You just try to get in the way and do like an invisible shield. Justin is very competitive, so he’s going to continue to play until the whistle is blown. So it was a good thing that, even though the play was picked off, he still kept competing, kept playing.

“That’s a good thing to see out of your quarterback because some quarterbacks just shut it down. You see Tom Brady, they’re not running (to make a tackle).”