Timberwolves’ Game 4 loss to Thunder raises a gigantic question: Where did that defense go?

At their core, the Timberwolves are a defensive team. They pride themselves on being one of the best teams in the NBA at that end of the floor.

But should they lose this Western Conference finals, and that’s all but a done deal after the Oklahoma City Thunder defeated them 128-126 on Monday night for a 3-1 series lead, they will look back and say their defense wasn’t quite what it could’ve been in both years they made it this far.

The Wolves couldn’t quite solve Luka Doncic, Kyrie Irving and the height of the Mavericks a season ago. This season, in three of four conference finals games so far, they have been loose in their coverages, a little too indecisive on when to help in the gaps, and they have made game plan mistakes that have allowed not just Shai Gilgeous-Alexander to have big nights but his teammates Jalen Williams and Chet Holmgren as well.

Then when the Wolves would force a miss, they couldn’t end the possessions. The Thunder grabbed 19 offensive rebounds for 24 second-chance points.

“They outplayed us, outrebounded us, got more of the 50-50 balls,” Wolves guard Anthony Edwards said. “Wanted it a little bit more.”

Though the Wolves had 30 second-chance points of their own, it makes it all the more disappointing that a game there for the taking could have been the Wolves’ if they had been just a bit better on their strongest end of the floor.

They didn’t throw as many bodies at Gilgeous-Alexander (40 points) as they did in Game 3, forward Jaden McDaniels said.

“That last game we played, he was seeing like three or four bodies,” said McDaniels, who scored 22 points. “I feel like this game, he only seen like the man guarding him and the main gap person. So, we’ve just got to get better at our game plan mistakes.”

Another of those game plan mistakes — the difference between winning and losing this deep in the playoffs — was letting Williams get comfortable, specifically by getting to his left hand, point guard Mike Conley said.

Williams had 34 points, 14 in the fourth quarter, and he responded with big shots any time the Wolves made a run. He hit a pair of threes in the fourth quarter that extended four-point Thunder leads to seven twice. Then Holmgren joined him in the clutch with nine points on 4-for-5 shooting. The Thunder shot 16-for-37 (43%) from three-point range.

“They’re really patient,” Conley said. “I think they took their time in trying to find a matchup or patient as far as finding gaps, and when we were too much in the help, they were getting off of it real quick. …

“It was a poor job on our end of doing the little things like keeping guys to their not-so-dominant hand, especially Williams late, getting to his left. Stuff like that was a big emphasis on this game.”

Contrast the production of the Thunder’s top names with the Wolves’. Edwards took just two shots in the first half before finishing with 16 points on 5-for-13 shooting with six assists.

“Definitely not the points I wanted to get, but they didn’t really let me get too many shots off,” Edwards said. “They did a good job of that. Every time I had the ball, they showed me a major crowd. So just making the right play and getting off of it. Our guys hit shots tonight, so big shoutout to them.”

Conley said the Thunder did a good job of crowding Edwards at the top of the floor, where the Wolves like to run actions for him. That made it harder for him to score. Edwards said he had to fight the urge to shoot and kept making the right play. It worked in that sense, because the Wolves shot 51% overall and 44% from three-point range.

“It’s an urge that I want to get the ball in the rim, put it up there,” Edwards said. “But you don’t want to take bad shots and get your team out of rhythm. So, I was just playing the game the right way, man. And that’s what we did tonight as a team.”

Nickeil Alexander-Walker scored 23 points and Donte DiVincenzo had 21 off the bench as they took advantage of the attention Edwards was drawing. Alexander-Walker added six assists, and DiVincenzo had five. That helped pick up the slack for Julius Randle, whom the Thunder locked up like they did in Game 2. Randle scored five points on 1-for-7 shooting Monday.

“I think it was just a lot me just spectating,” Randle said when asked what the Thunder did to take him out of the game. “I got to figure out a way to get myself involved in actions. I think I didn’t take my first shot in the second half until there were 20 seconds left in the third quarter. I gotta figure out a way to get myself in position to be more aggressive, rather than just standing, spectating or trying to crash the glass. Or I can just find other little things to do.”

But the Wolves posted 126 points on the best defense in the NBA. During the regular season, they were 20-3 when they scored 120 points. With a defense like theirs, that’s usually a recipe for success, even when they committed 23 turnovers.

The Thunder answered every punch the Wolves threw. This was one of the big questions about Oklahoma City entering the playoffs: Would the Thunder have legitimate second and third scoring options, especially in clutch time, to navigate the playoffs? They answered that in a big way Monday.

BOXSCORE: Oklahoma City 128, Wolves 126

“At the end of the day, you got to look at why. … When you look back at the game, it says it all right here,” Alexander-Walker said, looking down at the boxscore in front of him. “They had 19 offensive rebounds. We knew that’s what they did. We know they wanted to turn us over, and we talked about it. Game 3, we didn’t let them do that, and we saw the result. Everything is out there. There are no secrets. They know how to beat us. We know how to beat them.”

But the Wolves have only done it once. Now they have to beat the Thunder twice in a hostile road arena, one in which they looked overwhelmed at the start of the series, to extend their season.

“You’ve got to come to play or the season’s going to be over,” McDaniels said.

Coach Chris Finch said the team still had hope it could come back in the series, before adding: “This isn’t the formula to get it done. That’s the more important thing to take away from tonight.”