Arizona quarterback and former Serra High standout Khalil Tate is ready to show USC what it missed

The season had started badly for Khalil Tate, the young quarterback battling injury and stuck on the bench.

So when his Arizona Wildcats had a bye on the schedule, he decided to spend the weekend at home in Southern California and maybe watch his old high school team.

Showing up at a Gardena Serra game in late September, he sought out his former coach and talked about how badly he wanted a chance to start at Arizona.

“Once they put me in, they’ll never take me out,” he said.

It was a bold statement from a sophomore who had played only sporadically. It was also prescient.

In the month since then, Tate has taken command of the Arizona offense, propelling his team to four straight victories with an astronomical 1,583 yards in total offense and 14 touchdowns.

His instincts and quick feet make him a constant threat on zone-read runs. Though he throws less than 20 times a game, a strong arm and 69% completion rate force defenses to respect the pass.

All of which concerns No. 17 USC in its Pac-12 Conference showdown against the No. 22 Wildcats at the Coliseum on Saturday night.

“When you have to stop the run and pass, that makes for a hard day,” USC coach Clay Helton said.

Both teams have one conference loss, so the game will go a long way toward deciding who gets to play for the Pac-12 championship. It has additional meaning for Tate.

Coming out of high school late in 2015, he figured to sign with the Trojans, if only because they had recruited a string of Serra players, including Robert Woods, Marqise Lee and Adoree’ Jackson.

But USC coaches weren’t sure how they wanted to use him. The program had taken a previous Serra quarterback, Jalen Greene, and converted him to receiver.

Arizona had no such doubts, believing Tate would fit perfectly into coach Rich Rodriguez’s spread offense.

When Tate chose the Wildcats, Helton had a premonition: “I remember saying to myself, ‘Gad-dawg, that guy’s gonna be a pain in the butt.’ ”

Tate would need a while to adjust to the next level. Easygoing by nature — and only 17 when he arrived in Tucson as an early enrollee — he was a little overwhelmed by college football.

“Khalil always had a lot of fun in high school,” Serra coach Scott Altenberg said. “Now, he was like, ‘This is serious.’”

Tate recalled: “I was just a fish in the sea, trying to find my way somewhere.”

The Wildcats planned to redshirt him in his first fall, but had to shift gears after several quarterback injuries.

Pressed into action, the freshman struggled through all or parts of seven games. In his only start — a 48-14 loss to USC — he ran for 72 yards and passed for 58 with an interception.

“It was pretty embarrassing,” he said.

Back in high school, Altenberg had teasingly called him “Brett Favre” because, like the former Green Bay Packers star, he threw some risky passes. After the 2016 season, Arizona worked with him on patience and football knowledge.

“He’s always had a great natural throwing motion,” Rodriguez said at a news conference. “It’s just understanding the offense and the timing of it, and each particular play.”

Tate began this fall as the backup to Brandon Dawkins. Playing late in the opener against Northern Arizona, Tate suffered a sprained shoulder and had to sit out much of the next three weeks.

When the injury healed, he made the brash prediction to Altenberg.

“He seemed really ready to play,” the high school coach said.

Arizona’s road trip to Colorado in early October provided an opportunity. Dawkins got knocked out of the game by a late hit.

Tate wasted little time. On his second drive, he kept the ball on a zone-read to the right, swerving to avoid one tackler and another, for a 58-yard touchdown. It was the beginning of a highlight-reel performance.

Pure speed took him 28 yards for a second score around left end. The yardage began to pile up in multiples of jukes, cutbacks and weaving runs.

By the time Arizona secured a 45-42 upset victory, Tate had amassed 327 yards rushing, a FBS single-game record for a quarterback.

“I used to play basketball and I was a point guard,” he said. “I would see open guys down the court … playing football, it helps to have that vision.”

The following weeks brought more big performances against UCLA, California and 25th-ranked Washington State. His pass efficiency rating rose to 187.5 and his rushing average of 154.3 yards lifted him to second in the nation.

“You have to defend him every single play,” UCLA coach Jim Mora said. “He makes you miss and when he gets in the open field he is spectacular.”

With an explosive athlete at quarterback, Arizona — picked to finish last in the Pac-12 South — became dangerous, breaking into the College Football Playoff rankings this week.

“You want to be relevant more at the end of the year than the beginning of the year,” Rodriguez said. “The guys worked hard to get to that position, but you have to keep winning to stay there.”

Which means the Wildcats will need their new leader to stay hot.

Helton wouldn’t divulge his plans to contain Tate, but did talk about disciplined defense and limiting long gains, saying, “Once he gets into the secondary level, there’s no stopping him.”

Tate would love to show some of that magic against the Trojans.

A big win might erase the memory of last season’s stumble. Plus, family and friends will be watching from the stands.

Mostly, though, he wants to keep making good on his prediction.

“Any play, I feel confident,” he said. “I know what I can do.”

david.wharton@latimes.com

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