KIRKLAND, Wash. – When Mike Holmgren looks at Lofa Tatupu, he sees a representation of his Seattle Seahawks’ defense: young, aggressive, and only going to get better with experience.

He also sees a thriving rookie with football instincts passed on by his father, Mosi – a player many scouts considered undersized and too slow to play middle linebacker in the NFL.

“He’s new. He’s young. He’s athletic,” Holmgren said. “He makes a mistake now and then, but he makes up for a lot of stuff with how hard he plays.”

Seven games into his rookie season, Tatupu is firmly entrenched as the Seahawks’ middle linebacker for years to come, shoring up a revolving door at the position during Holmgren’s tenure. Since Holmgren’s arrival in 1999, Seattle has started seven players in the middle of his defense. That should end with Tatupu.

The rookie is leading Seattle in tackles with 44 entering this week’s bye. He also has a pair of sacks and an interception. He’s part of a defensive makeover in the off-season that includes seven new starters.

“Lofa is a special guy. He understands football, he thinks football,” said linebackers coach John Marshall.

Yet, there was plenty of doubt throughout the league when Seattle traded up nine spots in the second round of the 2005 draft to pick the 6-foot, 238-pound Tatupu, who left Southern California after his junior year with two national championships in tow.

The Seahawks looked past Tatupu’s drawbacks. They saw the instincts on film, part of the lineage passed on from his father, who played 14 years in the NFL. Tatupu rarely made a wrong step, and was always around the ball.

But doubt is nothing new for Tatupu. He thrives because of it.

Tatupu was a standout quarterback and linebacker while coached by his father at King Phillip Regional High School in Wrentham, Mass. It was a trying time for both father and son, despite the success Lofa achieved.

“It was a struggle … I’m a dad and a coach, and we’d be butting heads,” said Mosi, who coaches at Curry College in Milton, Mass. “I look back on it and it was great to be around him.”

Yet Lofa couldn’t get a Division I scholarship offer. Both Boston College and Connecticut scoffed at his size and speed.

Tatupu went to Division I-AA Maine, where he was the Black Bears’ second-leading tackler as a freshman. He still wasn’t satisfied, still carried the dream of playing in Division I-A. Tatupu wanted to be closer to his mother, Linnea, who lived near San Diego. He targeted San Diego State, but the Aztecs would not offer him a scholarship.

So, Tatupu followed his father’s footsteps and landed at USC.

“There is just tremendous talent over there and the coaching was unbelievable,” Tatupu said.

With coach Pete Carroll willing to take a chance, Tatupu developed into an All-Pac-10 selection, starting all 25 games in his sophomore and junior seasons. His father wanted Tatupu to return for his senior year, perhaps making a run at the Butkus Award, but Tatupu felt it was time to help his family.

“My family was struggling a little bit. I’ll just leave it at that,” Tatupu said. “But part of it is selfish, I’m not going to lie. I was thinking what more can we do (at USC)? I felt I was capable of making the jump and I didn’t think another year was going to make that big a difference in being able to.”

In training camp, Tatupu split time with second-year linebacker Niko Koutouvides, but it was quickly apparent Tatupu could win the job.

He had a stinging welcome to the league when Jacksonville’s Fred Taylor nearly ran over Tatupu in the season opener. But he sacked Michael Vick in Week 2 and had 10 tackles in Week 4 against Washington.

Tatupu has shown versatility, too. Due to injuries, he played in Seattle’s nickel package for the first time against St. Louis, when he had nine solo tackles and his first career interception.

Holmgren also got a laugh from Tatupu’s enthusiasm in that game. After St. Louis returned the opening kickoff for a touchdown, Tatupu begged to be put on the kickoff coverage unit.

It’s just that type of fervor Holmgren hopes will continue to spread through Seattle’s 10th-ranked defense.

“That will make a good movie some day,” Holmgren quipped. “But he’s a pleasure to have around. I love the guy.”