More than 10 years have passed since Jonathan Givony, now at ESPN, wrote these words in his pre-draft scouting report on Russell Westbrook:

Defensively, Westbrook is nothing short of outstanding, as evidenced by the phenomenal work he did locking down the three top scoring guards in the Pac-10 this season, O.J. Mayo, Jerryd Bayless, and James Harden. He is long, strong and very fundamentally sound, getting into a terrific defensive stance on every possession, moving his feet incredibly well, and being absolutely tenacious getting after his matchup.

Boy, oh boy, have things changed.

The Brodie’s offensive skills developed beyond what scouts and likely the Oklahoma City Thunder ever imagined. His usage rate crept above 30 by Year 3, when he made the first of his seven All-Star appearances. Superstar guards rarely ever pair one-man-army offensive numbers with elite defense—Chris Paul is a godlike exception here—and Westbrook is no different. Since his ascent to stardom, his defensive effort has waned. He has, after all, had to conserve energy to jumpstart the Thunder’s attack.

Oklahoma City has mostly survived Westbrook’s inattention. The team allowed a solid 104.6 points per 100 possessions last season with the UCLA product on the court, down from 106.4 when he sat. The differential was positive again this season. It was even better in the 2015-16 campaign, when Kevin Durant and Serge Ibaka were still around.

Russ, as always, has rewarded his teammates’ extra defensive effort with superhuman offense. And they’ve needed it. The Thunder’s attack has long been anemic without its catalyst in the game. But even with Westbrook, the machine has been feeble in this year’s first-round series against the Utah Jazz.

The Thunder have scored a lowly 101.1 points per 100 possessions—no surprise given Utah’s stingy defense, led by the indomitable Rudy Gobert, and some bricky shooting performances from Westbrook and Carmelo Anthony. But their defense is a bigger problem. The Thunder cannot stop anything at the other end, where the Jazz have poured in 108.7 points per 100 possessions. And Russ is one of the main culprits.

It starts in transition. Westbrook’s unwillingness to run toward his own basket is his most egregious habit . He’s often the last man back on Utah’s run-outs, and even when he’s not, he rarely makes an effort to stop the ball. He’ll instead watch aimlessly as Ricky Rubio floats by:

Or he’ll do whatever the hell this is to Gobert while Joe Ingles swoops to the corner for a rhythm three:

The Thunder haven’t suffered too much from Westbrook’s slow-poke jogs to the defensive end; Utah’s scoring a brutal 0.96 points per possession in transition, although it’s running at a high rate relative to the regular season.

The reigning MVP has, though, had a detrimental impact in the half-court, where he often seems interested in making just one or two movements each possession before calling it a day. Westbrook has mostly guarded Rubio, who often drifts off onto the wing so Donovan Mitchell can run the show. That places him in help position, but the “help” isn’t always forthcoming. He’s usually diligent about not straying far from his own assignment, but too often he stands upright and forgets to rotate:

Here, Westbrook needs to zone up the weak side and prevent the corner three. If he leaves Rubio open, so be it. But as all his teammates collapse to prevent the drive, he stays frozen in the same spot for five fatal seconds.

Sometimes he’ll even forget the basics:

As soon as Joe Ingles crosses up Paul George in this situation—I can’t believe I just wrote that—Westbrook needs to sprint in and defend the pocket pass to Gobert. That maneuver is part of any conventional pick-and-roll coverage, and let’s remember he’s guarding Rubio, not really a scheme-busting shooter.

I trust you can spot the mistake yourself in this next example:

Westbrook’s stance is the common denominator in each of these clips. He’s upright and ball-watching. Even if he can make up a step with his athleticism, he’s giving Utah’s players a two-step head start.

The Jazz, now leading 3-1 in this series, won’t show any mercy. As ESPN’s Zach Lowe detailed back in November, Quin Snyder’s offense—an egalitarian onslaught of pick-and-rolls and ball reversals—is predicated upon giving his players mini-advantages throughout each possession. The Jazz force opposing defenders to make decisions and stay on their toes.

Westbrook’s been on his heels. And he’s had no place to hide.

Despite being undisciplined off the ball, Westbrook has always been a capable on-ball defender, and sometimes, the potential to defend means more than actually defending. Teams seek out mismatches against slower and smaller dudes, and they’ll go back to those matchups over and over. During their 2016 Finals victory, the Cleveland Cavaliers offense became “find Stephen Curry.” Oklahoma City has never had that problem with Westbrook, who teams rarely target at the point of attack.

Until now.

The Jazz have no qualms attacking Westbrook in the pick-and-roll, knowing he’ll default to upright mode after the screen and leave his teammates scrambling. In the third quarter of Game 4, Billy Donovan countered by switching 1 through 5 so his team could avoid overcompensating for its MVP’s unwillingness to chase around picks. The Jazz got a post-up against Westbrook on the very next possession:

I don’t mean to harp on Russ. I love watching him play, and statistically speaking, he’s still not the problem. In their three losses, the Thunder have been at their worst defensively when he’s on the bench. He has the best defensive rating of any Oklahoma City starter—though, at 106.9, this doesn’t say much.

Middling returns won’t cut it for a defense that needs to match Gobert and friends’ work at the less glamorous end. The Thunder were at that level for large portions of the year. They boasted the league’s fifth-ranked defense until Andre Roberson’s season-ending patellar tendon rupture in late January. Corey Brewer has done as much as he can in Roberson’s absence, but it takes a team effort to get over that kind of loss.

Russ has not been a part of that effort.

He and Anthony have left Brewer, Steven Adams and Paul George out to dry. And without a backstop like Roberson, the team looks spent. Now more than ever—with shots not falling, the personnel far from ideal and sitting in a 3-1 hole—Oklahoma City needs Westbrook to be that defender about whom scouts raved more than a decade ago.

We know he can do it.

It’s just a matter of whether he’ll decide to.

Follow Nate on Twitter @NateWolfNBA.

Follow NBA Math on Twitter @NBA_Math, Facebook, Instagram and YouTube.

Unless otherwise indicated, all stats are from NBA Math, Basketball Reference or NBA.com and are accurate heading into games on April 25.