USC Coach Lane Kiffin watches practice last spring. (Gary Friedman / Los Angeles…)
USC tailback Javorious Allen broke through the line of scrimmage and heard the official's whistle ending the play, but he kept running more than 40 yards to the end zone.
That, perhaps, was the most telling event Saturday during USC's workout at the Coliseum.
It showed that Allen, a redshirt freshman from Florida, was back from a hamstring strain, or at least willing to play through the final stages of recovery from the latest in a series of injuries that have kept him sidelined.
It was no coincidence that Allen's first extended practice time came the day after USC announced that tailback Tre Madden would be lost for the 2012 season because of a torn knee ligament.
"I knew I had to step up and make a move for my team," said Allen, known to coaches and teammates as "Buck."
It remains to be seen what moves, if any, Coach Lane Kiffin might try in the wake of Madden's absence from the tailback rotation.
The converted linebacker appeared on track to supply the Trojans with a big-back presence and the capability to operate as a runner and passer from the wildcat formation.
Kiffin described Madden as "one of the most valuable guys on our team" because of his size-speed combination.
"The sky was the limit," Kiffin said, "and it will be when he comes back."
In the meantime, the Trojans will look to the 6-foot, 215-pound Allen and incoming freshman Nelson Agholor to augment a tailback corps that includes only two other scholarship players — returning starter Curtis McNeal and D.J. Morgan.
USC coaches had regarded the versatile Agholor primarily as a receiver. But the 6-1, 180-pound Florida native will be given a long look at tailback when he arrives in the summer.
"We know that he can do some stuff back there," Kiffin said, "and that would give us someone that we know has hands out of the backfield."
Allen will try to make his case during the Trojans' final three spring workouts, which conclude with next Saturday's scrimmage at the Coliseum.
Allen said he was still not 100%.
"Once I get fully healthy and get confidence in myself, I feel like I can be that big back," he said.
Running backs coach Kennedy Polamalu likes Allen's size and strength. He intends to give him as many repetitions as he can handle during the final week.
"He's just learning to see the game a little quicker right now," Polamalu said. "All the body parts are moving — he's still looking around. He's got those eyes rolling in the back of his head."
Kiffin put a moratorium on live tackling as the Trojans try to survive their final workouts without a major injury. "Just trying to stay healthy and still get some stuff done," he said. … Starting quarterback Matt Barkley played a few series and had a pass intercepted. ... Kevin Graf, who opened spring practice at left tackle, on playing again on the right, where he started every game in 2011: "I'm going to play hard wherever they put me."