Dillon Baxter puts on a show during USC scrimmage

Greater San Diego has been fertile recruiting ground for USC, producing Heisman Trophy-winning running backs Marcus Allen and Reggie Bush.

Now comes freshman Dillon Baxter.

It’s too soon, of course, to know how Baxter’s Trojans career will play out.

But the early enrollee put on a show during USC’s scrimmage on Saturday, scoring on a spectacular 50-yard run that left several defensive players on the ground grasping helplessly at air.

The play reminded new Coach Lane Kiffin of Bush’s 2005 performance against Fresno State, when Bush amassed 513 all-purpose yards at the Coliseum.

“Phenomenal,” Kiffin said. “It didn’t matter who was there. Nobody could tackle him.”

While former Trojans running back Joe McKnight struggled trying to live up to the hype of those expecting him to be the next Bush, the 6-foot, 199-pound Baxter welcomes the opportunity.

The jump to college does not seem to have fazed a player who accounted for a state-record 79 offensive touchdowns last fall while playing quarterback for Mission Bay High.

“I don’t have the fastest straight-away speed, but I can make a couple dudes miss,” said Baxter, who finished the scrimmage with 94 yards in nine carries and also caught two passes. “Right now I’m just a pretty shifty back, but I’m going to work on getting bigger and just be a big shifty back.”

It remains to be seen how Baxter will perform in the fall, but his early performance has wowed teammates.

“We’ve got to get more of those San Diego guys out here,” quarterback Matt Barkley quipped.

Harris rising

Junior tackle DaJohn Harris made the defensive play of the day when he stripped the ball from quarterback Mitch Mustain and rumbled 52 yards.

Kiffin said Harris was “the surprise of the camp.” He also said the previous coaching staff indicated that Harris was, “maybe not a very good player.”

But Harris has been motivated by the arrival of defensive line coach Ed Orgeron and Kiffin’s pronouncement that all jobs were open.

Perhaps more importantly, he is playing with more energy after being treated for sleep apnea. Harris said an academic advisor recognized symptoms similar to those once experienced by former Trojans defensive end Kenechi Udeze.

Harris was subsequently evaluated by team medical personnel and has received treatment that has enabled him to sleep soundly in the evening and stay alert during the day.

“I can’t just fall asleep anywhere now, even though sometimes I wish I could,” he joked. “I can breathe better on the field and my stamina is a lot better.”

Quick hits

The offense scored five touchdowns in the first half but was shut out in the second.... Barkley had what he described as his best scrimmage performance since arriving at USC, completing nine of 17 passes for 173 yards and three touchdowns with no interceptions. Barkley connected with wide receiver Ronald Johnson on 22- and 70-yard scoring plays. Johnson finished with four receptions for 167 yards.... Mustain completed 10 of 21 passes for 144 yards, including an eight-yard touchdown to freshman receiver Kyle Prater.... Tailback Allen Bradford rushed for 27 yards in 10 carries.

gary.klein@latimes.com

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