If Lance Anderson had any hair, he might have been pulling it out. He’s too even tempered to do that, but he admits he has been frustrated.

Stanford’s defensive coordinator has watched his unit give up 31 points to Oregon, 38 to Notre Dame, 40 to Utah, 41 to Washington State and 27 to Washington.

By his count, the Cardinal have missed “over 50” tackles in the past two games. In a good game, he said, they miss 10 or fewer.

“It’s something we’ve struggled with all season long, and it’s a place we have to get better,” he said. “It’s hard to play good defense when you don’t tackle well.”

Stanford (5-4, 3-3 Pac-12) is a huge favorite over last-place Oregon State (2-7, 1-5) in Saturday’s home finale. But missed tackles have put the Cardinal, ranked No. 7 near the end of September, in bowl limbo with three games left in the regular season.

They need a sixth win to qualify for their 10th straight bowl game.

Saturday’s game Who: Oregon State (2-7, 1-5 Pac-12) at Stanford (5-4, 3-3) Where: Stanford Stadium When: 6 p.m. TV/Radio: P12Net/1050

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Letting receivers out of their grasp is one reason why the Cardinal rank 12th in the Pac-12 and 111th in the nation in pass defense, surrendering 266.3 yards per game.

“The other thing you track along with the missed tackles is the yards that it leads to,” Anderson said.

That is, missed tackles don’t necessarily result in a lot of yards allowed if a defense is sound in its pursuit.

“In the last two weeks, not only is the number high, but it’s led to a lot of yards after the tackles were missed,” he said. “That’s a huge key.”

Inside linebacker Sean Barton, second on the team in tackles after Bobby Okereke, said a breakdown in tackling can leave a defense exposed to a possible chunk play.

“Guys are there and in position to make the execution sound, and they whiff,” he said. “A lot of times with the missed tackles, the guys are in position to do their jobs and we’re counting on them to do their job. When they don’t do it, it creates a huge gap. … It can be devastating for us.”

Every team has significant injuries at this point in the season. In the case of Stanford’s defense, two injuries in particular have been critical. Starting safety Ben Edwards has been out since the fourth game of the season with an undisclosed injury and might not return this year. Outside linebacker Joey Alfieri has missed the past two games and might not be back until a bowl game.

“At the safety position, we’ve struggled with missed tackles all season long,” Anderson said, alluding mainly to starters Frank Buncom and Malik Antoine.

They’re not alone. Freshman cornerback Paulson Adebo, who’s second in the nation in pass breakups with 15, didn’t have a good game at Washington on Saturday.

“Maybe as a freshman, he had to take his lumps, and definitely in this one, he did,” Anderson said. “He was a big culprit in the missed tackles in this game. He’s very willing, but in this game, the technique and the lunging and things like that were not what we needed.”

On the other hand, he said, redshirt senior cornerback Alijah Holder “played better than what he has in previous weeks.” Holder has been plagued by injuries the past two years, but Anderson said he hoped the last game “is a sign that he’s getting back to the old Alijah Holder.”

The defensive line, meanwhile, is often pushed around. Last year, Harrison Phillips led FBS linemen with 98 tackles. This year, no lineman has more than 34.

Tom FitzGerald is a San Francisco Chronicle staff writer. Email: tfitzgerald@sfchronicle.com Twitter: @tomgfitzgerald