Arizona’s defensive line needs help immediately.

Defensive tackle Saneilia Fuimaono needs to make a lasting impression by January. It may be the perfect fit.

Fuimaono, a 19-year-old freshman from Kaneohe, Hawaii, started in place of struggling defensive tackle Justin Washington against both Stanford and Oregon and could make his third career start at USC on Saturday.

Given his situation, the opportunity couldn’t have come soon enough.

Fuimaono is of the Latter Day Saints faith, and come January, the 6-foot-2, 306-pound defensive tackle will be gone. The true freshman will leave for a two-year mission after the season and, if everything goes as planned, will return to Arizona in 2014 to continue his Wildcat career.

The pressure is on for Fuimaono to produce sooner rather than later.

“I’m trying to shorten that learning curve and grow and mature as quick as possible,” Fuimaono said.

Fuimaono’s opportunity to contribute could have come a year earlier, as he signed with the Wildcats in 2010 and was expected to be part of that recruiting class. But the All-American wrestler tore his tricep in a match and chose to grayshirt, prolonging his enrollment until January of 2011.

“It’s not like he’s been training for this moment, he’s been waiting to get healed up,” said defensive line coach Joe Salave’a. “He’s making progress and he’s got to make progress. That’s the only thing we ask him; he’s got to get better but we don’t have the luxury of time as well.”

Fuimaono’s showed flashes so far, racking up three tackles — one for a loss — in limited action. And with Arizona’s defense giving up 854 rushing yards over the last three games, the Wildcats need Fuimaono to learn on the fly and ramp up the production.

Washington, a 2010 freshman All-American, was supposed to lead the Wildcats’ defensive line. But with only 10 tackles and no sacks through four uninspiring games, Washington’s “just not playing as well as he needs to,” said head coach Mike Stoops.

With no one on the defensive line separating themselves thus far, a starting gig is Fuimaono’s for the taking. Those prospects will be partially determined by how he fares against the USC Trojans this weekend.

But once January hits, the true challenges begin for both Fuimaono and the Wildcats. While on his mission, Fuimaono will be away from football and Arizona for two years, but he says he’ll have to work out one hour per day on his mission.

The rules have been changed to cater to athletes, he said.

“About five, six years ago, they were losing a bunch of guys playing Division I football so they were able to allow the Division I athletes to train,” Fuimaono said. “I have that plan going on so I’m just going to try and train and stay in football shape as much as possible.”

But Salave’a explained staying in shape isn’t the only factor in a situation like Fuimaono’s. By being absent for two years, the lineman and his teammates lose chemistry.

“You’re trying to build something, you’re trying to build continuity, get a little history going and of course whenever you stop with that your progress and everything stops as well,” Salave’a said. “You never know what comes back after the fact.”

But Stoops and Arizona believe in Fuimaono enough to take a calculated risk. If it weren’t for that risk, Fuimaono wouldn’t be in Tucson.

“It wasn’t my first choice. It was definitely my mom’s choice. As time went on, Arizona kind of came on the rise and when I came on my visit, it kind of sealed the deal,” he said. “The big thing was how they honored my faith and my religion, allowing me to go on my mission after the season.”

While Fuimaono’s mission will begin in January, his current mission lies between the lines. He’s battling for a starting job, hoping to make a lasting impression before he heads out of Tucson, all while giving Arizona’s defense the shot in the arm it’s desperately looking for.

“I’m just taking it one day at a time, trying to prepare myself and take care of the details and the big picture will take care of itself,” he said. “I try to be a sponge and try to soak in as much knowledge from as many players and coaches as possible.”