The line leader

As USC prepares for the toughest part of its football schedule the Trojans are counting on their playmakers.

Quarterback John David Booty, receivers Dwayne Jarrett and Steve Smith, running back Chauncey Washington and linebackers Rey Maualuga and Keith Rivers are among those who must figure prominently on Saturday against Oregon and remain healthy and productive in the coming weeks against California, Notre Dame and UCLA.

But the player the Trojans can least afford to lose will not pass or catch or run with the ball, nor will he intercept a pass or record a sack.

Senior center Ryan Kalil might not show up prominently on the opposing team’s scouting report, but he is the Trojans’ most irreplaceable player.

“He’s like the cog in the whole thing,” Coach Pete Carroll said.

Kalil’s value to the Trojans goes well beyond his calls along the line of scrimmage and his blocking.

The three-year starter and team captain is the linchpin not only to the offensive line but also to the Trojans’ psyche.

“I don’t know where we’d be without him,” All-American tackle Sam Baker said.

A computer-savvy film buff, the 6-foot-3, 285-pound Kalil annually produces elaborate team-related films to ease the monotony of training camp. Photos Kalil comically manipulates and inserts into otherwise serious presentations often break up meetings during the season.

“Coach Carroll has definitely given me a wide range to express my own personality and creativity,” said Kalil, who grew up in Corona.

Kalil, however, is also more than the Trojans’ film-editing cut-up.

Since arriving from Anaheim Servite High in 2003, he has developed from a quiet freshman into vocal leader. Last season, Kalil was selected All-Pacific 10 Conference after snapping the ball for an offense that featured two Heisman Trophy winners in the backfield and three offensive linemen who were selected in the 2006 NFL draft.

This season, he anchors an offense that features a triangle of first-year starters at quarterback and both guard spots.

“He’s like a second quarterback out there,” offensive line coach Pat Ruel said. “Ryan’s the one that’s pulled everything together. He’s our focal point.”

It was Kalil who animatedly implored coaches to keep running the ball during the Trojans’ game-winning, fourth-quarter drive against Arizona State.

Two weeks later, with the Trojans trailing by 23 points in the second half at Oregon State, it was Kalil who called teammates together on the sideline.

“He took off his helmet and said some stuff in that circle that was crazy; I almost cried,” guard Chilo Rachal recalled. “He said, ‘We’ve got to go. We’ve got to dig deep. This is what we’re made for.’ It was like Braveheart-type stuff.”

The Trojans’ comeback came up just short when Oregon State tipped away a two-point conversion pass, but USC kept alive its slim hopes for a Bowl Championship Series title-game berth by routing Stanford.

Now, as they face three ranked teams in their final four games, the Trojans will turn to experience to see them through.

No one has more than Kalil, who evolved from a 150-pound high school freshman into an NFL prospect.

Kalil credits his father, Frank, for showing him the way.

Frank Kalil played college football at Arkansas and Arizona, was drafted by the NFL’s Buffalo Bills, and played in the United States Football League. He stayed in the background, never pushing, when Ryan was a youngster, but when his son started high school and said he was committed to getting the most out his ability, Frank jumped on board.

“His whole thing was, if he was going to help me he was going to help me. It was going to be his way or no way,” Ryan recalled.

Under his father’s guidance, Kalil began a serious weightlifting and diet program. Extra technique work was a staple of weekends.

“What I did was basically point him in the right direction and lead him where he wanted to go,” Frank said.

Kalil played tackle throughout his high school career. During the summer before his senior season, he attended several camps, which serve as evaluation opportunities for the college programs sponsoring them. His father urged him to not sit back, to push to the front of the line at USC.

Though it was against Ryan’s nature -- “I’m the guy screaming, Ryan is someone who will politely put you on your back,” Frank said -- Kalil bulled his way to the front and volunteered to take repetition after repetition in one-on-one drills against all comers.

Trojans coaches later summoned him to the football office and offered him a scholarship, telling him he would move to center. Kalil committed on the spot.

“I don’t think I’d done cut-sees since third grade at the water fountain,” Ryan recalled. “But my dad was right.”

Kalil backed up senior Norm Katnik as a freshman, then braced for a challenge for the starting job in 2004. USC’s recruiting class that year featured center Jeff Byers, the Gatorade national high school player of the year from Colorado.

“We brought Jeff in thinking he would give [Kalil] a run for his money,” Carroll said.

Kalil said he respected Byers and recognized his talent, “but he wasn’t going to take my job.”

Nearly three years later, Kalil still has it.

Byers was moved to guard but has been plagued by injuries. During training camp, redshirt freshman Nick Howell switched from tackle to center to shore up depth, but the Trojans cannot afford to be without Kalil.

Booty, a fourth-year junior, roomed with his center during their first two years at USC and said the connection helps on the field.

“He can tell if I’m not feeling quite good about something where nobody else would know that,” Booty said. “We had many a talk at night laying in our beds. I consider him a brother.”

Kalil’s real brother, Matt, a 6-7, 275-pound junior offensive lineman at Servite, has committed to the Trojans, so the Kalil legacy will apparently continue at USC.

Before he moves on to the NFL, Ryan would like nothing more than to complete his Trojans career with a third national title.

It might be a longshot, but Kalil intends to make sure his teammates are ready to make a run.

“You don’t want, 10 years down the road, to look back and say you didn’t get the most out of your opportunity,” he said.

gary.klein@latimes.com