Mitch Mustain shines, Matt Barkley hurt during final spring scrimmage

There is no quarterback controversy at USC.

Sophomore Matt Barkley was the starter last season, maintained his status this spring and, barring injury, will no doubt be under center for the Trojans when they open the season Sept. 2 at Hawaii.

But on an afternoon when Barkley suffered a hand injury, senior Mitch Mustain stirred the fan base Saturday by passing for nearly 300 yards and five touchdowns in the Trojans’ final spring scrimmage at the Coliseum.

Mustain has sat behind Mark Sanchez and Barkley since transferring from Arkansas in 2007. He also, at times, was behind Aaron Corp, who transferred to Richmond after last season.

Not one to get overly excited about anything — most of his touchdown passes, after all, came against the second-unit defense — Mustain acknowledged after the scrimmage that he was encouraged by his prospects.

Why?

“One less guy in front of me,” he said, “and [I’m] playing pretty well.”

Mustain, freshman tailback Dillon Baxter, senior fullback Stanley Havili and senior receiver Travon Patterson were the other standout playmakers during a 98-play scrimmage.

Asked to assess his team heading into the off-season, first-year Coach Lane Kiffin, as usual, did not mince words.

“Our defense has a chance to be really good,” Kiffin said. “I think our offense has a long, long, long ways to go, especially in the run game.”

USC’s first-team offense irked Kiffin, who doubles as offensive coordinator, by going scoreless in the first half.

“We told the players at halftime, they were going to take their scholarship checks and give them back to the fans that came out today because it was an embarrassing performance,” Kiffin said.

Barkley responded by connecting with Patterson for a 41-yard touchdown early in the third quarter. But defensive tackle Jurrell Casey hit Barkley on the play, the quarterback’s right hand slamming into the defender’s helmet.

“Like throwing your hand full force into a wall,” said Barkley, who completed seven of 16 passes for 87 yards.

Barkley, who had surgery on his right wrist after last season, lay sprawled on the ground for several moments after the play and was examined by doctors on the sideline. He spent the rest of the afternoon with an icepack on the back of his right hand. A school spokesman said Barkley would be reexamined on Monday. Kiffin removed Casey from the scrimmage for knocking down the quarterback.

Baxter rushed for 129 yards in 13 carries and provided the highlight play when he took a handoff, spun twice behind the line of scrimmage and broke free for a 58-yard gain.

Asked whether he had seen that move before, Kiffin said, “Yeah, PlayStation 2. R-2 button.”

Said Baxter: “The second spin came out of nowhere. . . . I was able to make plays after that.”

Havili scored on touchdown pass plays of 28, 33 and 50 yards, all from Mustain, who finished 19 for 29 for 299 yards. Mustain also caught a pass from Baxter.

Kiffin praised Mustain for his work during the spring, but Barkley, who did not have a pass intercepted in four scrimmages, is the starter heading into training camp.

“We think we have two quarterbacks that can really help us win,” Kiffin said.

Kiffin is not as enamored of other parts of the offense. He said the Trojans have “zero depth” at receiver and wants more from the offensive line and running backs.

USC players now begin three months of off-season workouts. Training camp begins in August.

Quick hits

Linebacker Michael Morgan had seven tackles, linebacker Malcolm Smith six. . . . Cornerback Shareece Wright had five tackles and three pass deflections. . . . Patterson had five catches for 101 yards and two touchdowns. . . . Tailback Allen Bradford rushed for 48 yards in seven carries, Curtis McNeal 44 in eight and Marc Tyler 31 in seven. . . . Freshman receiver Kyle Prater caught an eight-yard touchdown pass from quarterback James Boyd.

gary.klein@latimes.com

twitter.com/latimesklein