Vainuku the early favorite at fullback

USC brings back a lot of talent at the skill positions in 2012, with quarterback Matt Barkley, running back Curtis McNeal and receivers Robert Woods and Marqise Lee all returning.

But there's one spot still open as spring practice nears and official preparation for next season approaches: fullback.

Trojans coach Lane Kiffin says redshirt freshman Soma Vainuku will get the first crack at replacing the departed Rhett Ellison, but he'll get competition from Simione Vehikite and Jahleel Pinner over the next several months, and potentially others, too. There are a number of Trojans with some experience playing fullback, like tight end Christian Thomas and defensive end Charles Burks.

And the interesting thing about the fullback slot this year is that it might involve quite a bit of carrying the ball -- or at least more than in past years. With only three running backs on the roster and the two experienced ones both weighing under 210 pounds, the fullback might also be the big back.

Vainuku would fit that role well.

"I would definitely embrace that," he said this week, after an unofficial team throwing session. "In high school, I was a fullback. But, really, I was pretty much a running back."

"Especially with the depth at running back for us this year, I could definitely see (running backs) coach (Kennedy) Pola asking me to get a couple reps at running back and helping them get a breather, being there for them."

There's that, and there's the aspect of pass-catching. Since he got to USC, Kiffin hasn't called for it as much as expected, but the fullback position in the Trojans' offense does have the potential to be serious safety valve -- especially considering that the team's tight ends are big-play threats more than short-route options.

"You gotta be able to catch the ball," Vainuku said. "You have to run a wheel or something a lot. You gotta be good in the flat. You gotta be elusive."

Vainuku was originally a Class of 2010 signee but didn't qualify academically and had to wait for the subsequent spring to begin classes. There was a thought that he could step right in for Stanley Havili last fall, but Kiffin made the decision in fall camp to move Ellison from tight end to fullback to give Vainuku time to develop.

Ross Cumming ended up spending significant time at the spot, too. And Vainuku used his redshirt year and excelled on the scout team.

Now, with a year in the system and a new class of early enrollees joining him last month, he's been one of a few players staying late after each of the throwing sessions and practicing his timing in the passing game with some of the walk-on quarterbacks.

"I feel comfortable right now," Vainuku said. "Having the guys come in the spring finally makes me feel old."