Anyone who watched the Chicago Bulls’ season-opening win over the up-and-coming Detroit Pistons probably came away with a few key takeaways.

35-year-old Nikola Vucevic turned back the clock, looking unstoppable with 28 points and 14 rebounds. Matas Buzelis’s sophomore breakout is officially official—the 21-year-old poured in 21 points, grabbed six boards, blocked three shots, and threw down multiple rim-rattling dunks. Josh Giddey delivered what felt like his near-mandatory double-double, while the bench duo of Ayo Dosunmu and Kevin Huerter combined for 29 points, 10 rebounds, and four threes.

Only two Bulls failed to score: Dalen Terry, who logged six minutes and took just one shot, and starting small forward Isaac Okoro. Acquired via an offseason trade, Okoro went 0-for-2 from the field and was largely unnoticeable during his 23 minutes on the court.

Isaac Okoro’s defense proved critical in Bulls’ win

Yet for a defensive ace, going unnoticed can be a good thing—much like a cornerback whose name is rarely mentioned throughout a game. The 6-foot-5, 225-pound Okoro was likely inserted into the starting lineup to defend All-NBA guard Cade Cunningham, Detroit’s one-man wrecking crew. And he did a terrific job of pestering him all night.

Cunningham scored 23 points, but it took 24 field goal attempts to get there. The fifth-year guard shot 8-of-24 from the floor and 1-of-6 from three-point range. A quarter of his points came from the free-throw line, and he finished with a minus-six despite the Pistons’ four-point loss.

When matched up against Okoro, Cunningham went 2-of-10 from the field and ultimately settled for more difficult looks. All six of his three-point attempts came with Okoro as his primary defender. The former Oklahoma State guard also committed a turnover while being pressured by the 6-foot-5 wing.

Okoro’s defensive performance was nothing short of impressive. Time and again, he expertly navigated screens, pressured shooters, and sealed off driving lanes. He tallied three deflections, recovered a loose ball, and even drew a charge.

Perhaps most impressive, Okoro posted a plus-17 in just 23 minutes of action. Despite not scoring a single field goal, he proved to be a difference-maker. For comparison, Vucevic was second on the team at plus-8. It’s only one game, but as expected, Okoro is already proving consequential to the Bulls’ success. Chicago didn’t roster a rugged point-of-attack defender last season—now, Okoro is that guy.

At first glance, Okoro’s box score might look underwhelming: zero points, five rebounds, four assists, and not a single steal or block. Grabbing five boards and dishing out four assists is respectable, but overall, the numbers are surely disappointing.

Nonetheless, Okoro’s impact goes far beyond the box score. The Bulls likely wouldn’t have won without him in the lineup. After all, he was the one who defended Cunningham’s potential game-tying three-pointer with under 10 seconds remaining. Chicago doesn’t roster another perimeter defender of Okoro’s caliber, and with upcoming matchups against Desmond Bane, Trae Young, Zach LaVine, and Jalen Brunson in the coming days, it’s apparent that his staunch defense will continue to be critical to the Bulls’ success.