After missing the previous two games with a left ankle sprain, Cooper Flagg was back in the Dallas Mavericks‘ lineup Monday night, cleared to play and stepping onto the floor at Madison Square Garden for the first NBA game of his career in the league’s most storied arena.

What followed was not a tentative return or a feeling-out process, but a performance that reflected both his growing comfort at the professional level and the expanding responsibility he carries for the Mavericks.

Flagg finished with 18 points and seven rebounds in 28 minutes as Dallas overwhelmed the New York Knicks, 114–97, imposing pace and pressure from the opening minutes and never trailing. The victory improved the Mavericks to 18–26 overall and 5–14 on the road, while New York fell to 25–18 and 16–6 at home.

Cooper Flagg Was Cleared After Two-Game Absence

Flagg entered the game listed as questionable after missing Dallas’ previous two contests with a left ankle sprain. His availability was not confirmed until after pregame warmups, and his minutes were monitored closely once the game began. Even so, there was little visible hesitation once he checked in.

He attacked closeouts early, ran the floor hard in transition, and played through contact rather than around it — all signs that the ankle was no longer dictating his decision-making.

“I feel great,” Flagg said. “Coming back, obviously, I was a little restricted minutes-wise, but I felt great out there. I didn’t second-guess it or anything. Strength felt good.”

The lack of hesitation stood out to Mavericks head coach Jason Kidd, who emphasized Flagg’s energy and movement more than any box-score line.

“I thought he was good,” Kidd said. “I thought his energy was good. He looked athletic. It didn’t look like there was rust — maybe the only rust was his free throws. But besides that, he was Cooper Flagg to me.”

A First NBA Night at Madison Square Garden

Flagg had played at Madison Square Garden before at the college level, but this marked his first time on the floor there as an NBA player — and it showed in the attention, not the execution.

Monday marked his first NBA appearance in the building, and the stage — the lights, the noise, the significance — was not lost on him. Rather than shrinking from it, he leaned into the moment.

“It was incredible,” Flagg said of playing at Madison Square Garden as an NBA player for the first time. “It’s a great environment. They have really good fans, and it’s such a unique atmosphere in here. It was great, and I thought we played a good game.”

He consistently looked to advance the ball early, attacking before New York’s defense could get set. Several of Dallas’ early runs featured Flagg pushing downhill or finishing in the open floor, helping establish tempo that the Knicks never managed to slow.

Dallas opened the game on a 13–4 run and closed the first quarter ahead 31–22. The separation widened rapidly in the second quarter, as Flagg’s ability to convert stops into offense helped fuel a 44-point period that broke the game open. By halftime, the Mavericks led 75–47.

Production That Matches a Growing Role

Flagg’s return fit seamlessly into what has been a consistent rookie season. He is averaging 18.8 points, 6.3 rebounds, and 4.1 assists across 41 games, carrying a significant workload while remaining efficient.

He credited the team’s recent continuity — built while he was sidelined — for easing his transition back into the lineup.

“Those two games were huge for us,” Flagg said. “The guys built more continuity, the offense started flowing, and it was good carryover tonight.”

That continuity was especially evident in how quickly Dallas played. With Anthony Davis and Kyrie Irving sidelined, the Mavericks have leaned into pace, and Flagg has become a key driver of that identity — sprinting lanes, initiating early actions, and capitalizing before defenses can get set.

“You’ve got to have five guys guarding the ball and covering for each other,” Flagg said. “He’s going to make plays, he’s going to hit tough shots, but as long as we don’t let him dictate the pace.”

Defensive Responsibility on a Big Stage

Flagg’s night was not defined solely by scoring.

Defensively, he spent extended stretches matched against Jalen Brunson, operating within Dallas’ team concepts rather than chasing individual stops. The approach was collective: show bodies early, cover for one another, and prevent New York’s guards from dictating tempo.

“Coach said it — he’s one of the best,” Flagg said of Brunson. “You’ve got to have five guys guarding the ball and covering for each other. He’s going to make plays, he’s going to hit tough shots, but as long as we don’t let him dictate the pace.”

That mindset carried throughout the lineup. Dallas mixed coverages, rebounded aggressively, and immediately turned defensive stops into transition opportunities — a sequence that repeatedly short-circuited any Knicks momentum.

“I think it was team defense,” Flagg said. “We know who their guys are, who they want to go to. There were a lot of different guys stepping up and making plays. I thought we covered for each other really well tonight and played really good team defense.”

Cooper Flagg’s Return Helps Spark a Win

By the time Flagg exited for the final time, the outcome was no longer in doubt. Dallas had led wire to wire, built a margin as large as 30 points, and turned Madison Square Garden into a quiet backdrop for a road performance rooted in speed, spacing, and discipline.

“Just playing together,” he said. “Keeping the offense flowing, but it starts with our defense. When we guard and get out in transition, it sparks us and gets us going.”

For Flagg, the night accomplished multiple things at once: a successful return from injury, a confident first NBA appearance at Madison Square Garden, and another step forward in a season defined by responsibility beyond his years.

The Mavericks will look to carry that momentum home Thursday when they host the Golden State Warriors. Flagg, healthy again and unfazed by the league’s brightest stages, appears ready to keep pushing forward — wherever the schedule takes him next.

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