Manu Tahi used to own the school record in the 100 meters at Tonga High School in Nukualofa, Tonga. At age 19, Manu made the Tongan national rugby team. So when it comes to the run, he is closely monitoring the legs of his son, BYU running back Fahu Tahi.

Nothing gets by this father.

Fahu is rediscovering his legs, a pair of pylons he dominated with while at Granger High. The power in those limbs sort of wandered away the past three years during an LDS mission to Jacksonville and this past season as he tried to regain his mojo.

You could see it this past week during BYU's second major scrimmage of spring practice. When the Cougar offensive line was fresh and firing up, Tahi was his old bulldozer self, driving his legs past tacklers, shifting his hips, making conservative moves — which is his style — but accenting every step with force.

In 2003, that wasn't there. He had no first step. He didn't have the power he showed his freshman year when he traded time with another rookie named Luke Staley. This week, some of his old form was reborn.

"I feel like I'm getting closer," Tahi said following Thursday's scrimmage.

"He's getting better," said Manu, "but he still isn't back to where he was when he was in high school. I'd say he's 80 percent right now."

With scholarship backs Curtis Brown and Marcus Whalen missing drills and 2003 leading rusher Rey Brathwaite dismissed from school, Tahi is getting a lot of work heading into Saturday's Blue-White game in LaVell Edwards Stadium. (Brown has a sore hamstring, and Whalen is making up for lost academic time while dealing with personal business outside of school.)

It was a frustrating year for Tahi. In reflection, maybe the sophomore should have redshirted upon returning from his mission to Florida in November 2002 so he could get his best weapon, his legs, back in form. Although Tahi got to where he could bench press the NFL 225-pound lift an impressive 29 times, and he felt ready, his Michelins had no grip.

Right now, Tahi is 6-foot and 230, a few pounds lighter than he was during spring a year ago.

Slowly, he's regaining the explosion he had as one of Utah's top high school football recruits.

Most of the credit goes to conditioning coach Jay Omer. But a sizable chunk of Tahi's focus comes from his father, who has pushed him to do extra work, including running stairs on his own the past two winters after his mission. That Lance Reynolds, his former coach and the man who recruited him to BYU, has been reassigned to work with Tahi is a bonus, according to his father.

Manu knows Fahu's engine pretty well. He has been the force behind his football career.