LOS ANGELES ---Soma Vainuku is not your average fullback.
"(He brings) unique features (to the position) --the size and speed. They don't make many humans like that," said USC head coach Lane Kiffin. "It's great. If you can have a fullback that can block and be big but also can run, you have the potential to give some people some issues."
The speed Kiffin speaks of was even surprising to Vainuku.
Earlier this summer when USC players were timed in the 40-yard dash, Vainuku wasn't feeling like himself. He was ill and "sluggish," but figured he'd give it a shot anyway.
"I thought I was going to do horrible," he said. "Afterwards the strength coaches let me know what my time was and I was kind of blown away by it."
The time: 4.41.
Vainuku stands 6'0, 250-pounds.
He ran the fastest time of all of the USC running backs, save D.J. Morgan, who didn't run because he was sidelined with turf toe, and Silas Redd, who wasn't with the team yet.
Vainuku has showed off that speed while ripping off a few long runs during fall camp. The coaches agree he's a "capable" ball carrier and the redshirt freshman did plenty of it in high school.
As a senior, he ran for 2,202 yards and 38 touchdowns while leading Eureka to a CIF North Coast Section championship.
In his high school career, he ran for 4,502 yards, and 79 touchdowns before originally signing with USC in February of 2010. He did not qualify academically and later enrolled in the spring of 2011.
He can be a ball carrier and might even be that big back the team needs but that's not his role.
"Right now, his first role is to be the fullback and he's getting better every day and then when he does get the opportunity to get the carries, he's done pretty good at that too," said running backs coach Kennedy Polamalu. "We're just trying not to overwhelm him.
"He's never taken a college football snap in (a) live situation in the Coliseum or in a game situation."
When it comes to carrying the ball, Vainuku sees himself as a reliever of sorts.
"I feel comfortable carrying the ball. In high school, that's what I did," Vainuku said. "Here, they're giving me a couple of carries but that's just relieving some running backs, giving them a breather."
The fullback in the West Coast Offense is a dynamic position with duties including run blocking, pass blocking, and catching the ball in the flat. Vainuku's predecessors were guys Polamalu says helped the offense move the chains. The coaches want him to fit that mold.
"He's got to be a chain mover catching the ball, blocking, or possibly running it," Polamalu said. "Right now I'm just trying to get him in the mindset of, 'Hey, you're the fullback. Make plays with and without the football,' and he's growing every day."