UCLA linebacker Myles Jack’s knee injury is a torn anterior meniscus, and will almost certainly keep him out for the remainder of the season — as well as cast doubt on his future as a Bruin.

Head coach Jim Mora said Thursday that the tear will sideline the defensive star for four to six months, and said that he does not expect Jack to return in time for a bowl game.

“If he were, that would be a bonus that we’re not really even thinking of or counting on,” Mora said. “I don’t think it would be fair to put that type of pressure on him. … I think you have to be very careful when you start putting a timeframe on, but when you say four to six, there’s a little wiggle room there.

“So I think — I’m certain he’s out for the year.”

Jack got hurt on Tuesday, Mora said, when he bumped his knee against another player’s during a 7-on-7 portion of practice. He wasn’t able to straighten his leg, which indicated that a piece of cartilage was stuck in the joint, a diagnosis later confirmed by an MRI. He did not tear any ligaments.

Because the nature of the injury was identified so quickly — and because Jack hadn’t eaten that day — UCLA was able to rush him into a 3 p.m. surgery. Jack then had his meniscus stitched together, a process that’s necessary for a significant tear but one that also elongates recovery time.

Mora said he has not yet talked to Jack about staying in school or declaring for the NFL draft, but said they will discuss that in late November.

“It’s not where his mind’s out,” Mora said. “It’s not where his mind should be. … Ultimately, it’ll be their decision.”