Getting up to speed with his duties in the backfield has accelerated Joey Iosefa’s rise up the depth chart.

As much as any group, spring represents a season of opportunity for Hawaii’s running backs. Iosefa, a redshirt freshman who began learning the position last spring, is positioning himself for playing time in the fall with eye-catching performances in the Warriors’ workouts.

“Joey Iosefa’s been a great surprise,” UH running backs coach Brian Smith said. “He looks a lot quicker, he’s understanding the offense a lot better, getting a lot more comfortable, so he’s had a really good spring so far.”

The Warriors’ top two backs last season — Alex Green and Chizzy Dimude — completed their eligibility in the Sheraton Hawaii Bowl, creating a gaping vacancy this year’s group is aiming to fill.

“It motivates me and I see this as my shot,” said Iosefa, whose given name is Marvin but has answered to Joey most of his life. “I haven’t played for so long I’m going to give 100 percent effort every day.”

Although still classified as a freshman, Iosefa hasn’t played in a regular-season game since his senior season at Fagaitua High School in American Samoa in 2008. As a grayshirt, he didn’t enroll at UH full-time until last spring and was a redshirt in the fall.

An all-purpose standout at Fagaitua, where he played quarterback, receiver and safety, Iosefa dabbled at linebacker when he first joined the program before moving to running back.

He spent last season learning the basics at the position while Green became UH’s first 1,000-yard rusher since 1992.

“He’d never really been a running back before so the reads were new to him, the footwork was new to him, everything was pretty new to him,” Smith said.

Along with shedding some weight in the offseason, Iosefa’s growing confidence in understanding the offensive scheme has allowed him to play faster in his opportunities this spring.

He broke off a big gain in yesterday’s practice after catching a screen pass on the perimeter and made some tough inside runs on short-yardage plays.

“Not only is he physical but he plays real hard, too,” Smith said. “He plays though the whistle.”

The competition at running back includes junior Sterling Jackson, who also redshirted and entered the spring as the leading candidate to step in for Green.

“I think Sterling is showing he can do a lot of the things Alex was doing,” Smith said. “He just needs to translate it to the field and get comfortable in the offense and play with a lot of confidence.”

John Lister showed flashes of his potential last spring and redshirted in the fall. With Jordan Monico moving to linebacker, sophomore Hogan Rosehill is the only member of the group with a Division I carry. He ran the ball five times for 24 yards last season before suffering a season-ending knee injury.

“It’s wide open, so I hope they all see there is a great opportunity there,” Smith said.

“Competition’s great, it’s going to get them all better and we’ll see who really wants to play the most.”