USC lineman Viane Talamaivao out for season after tearing pectoral muscle

In a season marred by injuries, USC could at least hold out hope that its banged-up players would return eventually. All the players the Trojans had sent to the injured list did not have season-ending injuries.

Until Wednesday. Guard Viane Talamaivao was diagnosed with a tear in his pectoral muscle, sustained last Friday against Washington State. He will require surgery that will end his season and, in all likelihood, his college career.

“Very sad story,” coach Clay Helton said. “Viane has been a rock to us for four years. Very much a leader near and dear to all our hearts.”

Talamaivao took over the starting job shortly into his freshman season and has made career 37 starts. He has played too many games this season to qualify for a medical redshirt year. To do so, he would’ve had to play in less than 30% of USC’s games. He has already played in five.

Freshman Andrew Vorhees will replace Talamaivao in the starting lineup. Vorhees has seen extensive time in two games this season, at tackle against Texas when Chuma Edoga exited because of a wrist injury, and at both tackle and guard against Washington State.

“Really a smart individual,” Helton said. “Picks up the playbook extremely well. Has the athleticism to play tackle and the physical size to be an interior guard and has played extremely well since he’s been here.”

Helton was not optimistic that Edoga, who has a high ankle sprain, would be able to play Saturday against Oregon State.

“High ankle sprains, especially on a big kid, it’ll be hard,” Helton said.

USC has sustained a rash of injuries. Eleven starters on offense or defense — fully half of the starting team — has missed time because of an injury.

Against Washington State, USC found a new way to lose two players. In pregame warmups, receiver Jalen Greene and linebacker Jordan Iosefa collided and both were put in the concussion protocol.

“We’ve had some back luck lately,” Helton said, laughing bitterly. “With that happening, I was like, ‘All right, that’s about as much as I can take as far as injuries go.’ “

Bat man

When linebacker Uchenna Nwosu is rushing the passer, he doesn’t just think about how to get to the quarterback. He’s also trying to guess the quarterback’s next moves.

Nwosu considers “the quarterback’s timing, his trajectory, how low his [passes] are,” he said, and he studies film each week with that in mind. The big prize: A batted pass.

What has resulted is a pass-breakup machine, like stationing a butterfly net on one side of the defensive line. Nwosu had five pass breakups all of last season. He has eight in five games this season.

He has become a magnet around the quarterback. In consecutive games, he has intercepted a batted pass near the opponent’s goal line. The most recent one came when he intercepted his own knockdown, after the ball ricocheted off the offensive lineman’s facemask, on the three-yard line.

Safety Chris Hawkins called Nwosu “the best defensive player in college football right now.”

“I don’t know why QBs keep thinking they can throw his way,” Hawkins said. “It’s certainly not working out too well for them right now.”

Nwosu said he focused in the offseason on disrupting quarterbacks. USC practices batted ball drills every day, and Helton said Nwosu, a former high school basketball player, is particularly well suited to the task.

He is fast — “as fast as our slowest DB,” Hawkins said, a capable jumper and strong enough to bull-rush offensive linemen.

He has not just succeeded in breaking up passes. Before last week, he had 22 quarterback pressures, best in the nation among edge defenders, according to Pro Football Focus. He had one more hurry against Washington State.

“He’s always around the ball, always making plays,” linebacker Cameron Smith said.

zach.helfand@latimes.com

Follow Zach Helfand on Twitter @zhelfand