With Myles Jack lost for season, UCLA’s depth will be tested again

Another day, another season-ending injury to an important UCLA football player.

Myles Jack was the name Wednesday, as Coach Jim Mora announced the Bruins’ two-way star had undergone surgery for torn meniscus in his knee, an injury Jack sustained during a non-contact drill a day earlier.

Jack, a force on defense at linebacker and a fast, physical running back in goal-line and other short-yardage situations, is the third starter the UCLA defense has lost this season.

UCLA reported Tuesday that cornerback Fabien Moreau had sustained a broken foot during Saturday’s win over Brigham Young. Tackle Eddie Vanderdoes underwent knee surgery after being injured during the Bruins’ season opener.

Mora was blunt in disclosing Jack’s injury to reporters after UCLA’s practice on Wednesday.

“Myles suffered a knee injury yesterday and had surgery last night and he’s out for the year,” Mora said. “So that’s the end of it right there.”

Ninth-ranked UCLA (3-0) plays at No. 16 Arizona (3-0), the defending Pac-12 Conference South Division champion, on Saturday in Tucson.

Asked who would replace Jack in the lineup for that key game, Mora’s comments were again brief. “I wouldn’t talk to you about that even if I knew, and I don’t,” he said.

Mora had been philosophical a day earlier, discussing Moreau’s injury. “Guys are going to get hurt. Guys are going to get dinged up in games,” he said. “You’ll have adversity. It’s how you handle it that defines you.”

The Bruins do not hold a patent on injury problems, even among undefeated, top-10-in-the-rankings teams.

Sixth-ranked Notre Dame (3-0) has lost five starters, including quarterback Malik Zaire.

Third-ranked Texas Christian (3-0) has lost five starters on defense, with another suspended after his arrest for felony robbery.

Top-ranked Ohio State (3-0) lost its top two quarterbacks last season and still won the national title.

Mora made a point of highlighting those teams, and other examples, when he addressed his team about Jack’s injury Tuesday night.

“He went through a list of teams and said, ‘These guys got through it, so we have to as well,’ “ junior linebacker Deon Hollins said.

The Bruins have built depth that could allow them to cover their losses, a process that has taken four recruiting classes and three seasons of teaching.

UCLA’s win over BYU was highlighted by the play of reserves.

Running back Paul Perkins rolled up 219 yards against the Cougars, but with UCLA trailing by six points with five minutes left, Nate Starks was in the backfield.

“I heard my name called and for a second thought, ‘That’s crazy,’ “ Starks recalled. “I’m the next guy up when Paul’s gassed or needs a break. I’m going to go out there and do what I can to make plays. That’s what I did Saturday.”

Starks, a sophomore, gained 60 yards on the drive, with his three-yard touchdown run as the exclamation point.

And, as the Bruins held off the Cougars on their last possession, only six of the unit’s defenders were starters. Reserves Isaako Savaiinaea, Jayon Brown and Denzel Fisher were among UCLA’s top four players in tackles.

Linebackers Savaiinaea and Brown, both juniors, had their roles elevated after Kenny Young was ejected for targeting. Savaiinaea made a team-high 14 tackles; Brown was second with nine. Fisher, a redshirt freshman who replaced Moreau at cornerback, made seven tackles.

“As we have seen the last couple weeks, you can lose starters at any time,” Brown said. “You have to prepare as if you’re a starter.”

Eli Ankou, a junior, and Matt Dickerson, a sophomore, have been capable replacements for Vanderdoes.

“The only way to build depth is by playing guys,” Mora said. “I would have rather had guys who started the game in there at the end Saturday. But the fact that we were able to survive without that being the case will be positive for us down the road.”

Losing Jack is like losing more than one starter.

The 6-foot-1, 245-pound junior was one of the top linebackers in the nation. He had the strength to handle blockers in the run game and the speed to cover receivers in space. He was also a force on offense at running back and even returned a kickoff — for 29 yards — this season.

“It’s impossible to do what he does on the field,” Hollins said. “No one in the nation does. He was three players in one.”

The return of defensive back Ishmael Adams should help. He was reinstated to the team this week after he was not charged with a felony in connection to the theft of a cellphone from an Uber driver. Adams, a first-team All-Pac-12 cornerback last season, had lost his job as a starter but had been tabbed as the nickel back in passing situations. Safety Tahaan Goodman and linebacker Kenny Orjioke will see their roles increased.

The Bruins would like to mix and match defensive combinations according to the situation, but getting substitutes on the field can be difficult against a no-huddle team such as Arizona.

“The main thing is to keep everything in perspective and know you’re not going to replace Myles Jack,” Hollins said. “We’ve been losing a lot of All-American, NFL guys. Coach Mora said, ‘Next man up, close ranks.’ Coaches like to say that.

“As a team, as a player on the field, you have to take that on your shoulders. Other guys have to step up.”

chris.foster@latimes.com

Twitter: @cfosterlatimes