NEW YORK — For the seventh consecutive year, there will not be a repeat champion in the NBA.

The Celtics, after rallying to win Game 5 without injured superstar Jayson Tatum, were obliterated in Game 6 of the Eastern Conference semifinals, offering little resistance in a 119-81 loss to the New York Knicks at Madison Square Garden.

Jaylen Brown did what he could to carry a punchless Celtics offense (20 points, six assists, six rebounds) but coughed up seven turnovers and fouled out before the end of the third quarter.

Derrick White, brilliant in his 34-point eruption two nights earlier, played his worst game of the season, going 3-for-11 to finish with eight points, two assists and one rebound. The Celtics were outscored by 45 points with the veteran guard on the floor, by far the worst mark of his career. His backcourt partner, Jrue Holiday, went 1-for-8 and was a minus-34. Al Horford had 10 points and two rebounds and was a minus-33.

It was an ugly end to a series to forget for the Celtics, who were pushed to the brink of elimination even before Tatum ruptured his Achilles late in Game 4. Boston led by at least 14 points in each of the first five games but won just two of them.

The Knicks will advance to face the Indiana Pacers in the Eastern Conference finals while the defending champion Celtics enter an offseason fraught with uncertainty.

The last six NBA title-winners all failed to advance past the second round the following season.

The Celtics quickly fell behind amid a disjointed start that featured turnovers on two of their first five possessions. The Knicks ripped off a 7-0 first-quarter run while dominating the offensive glass, and Boston looked tense early, misfiring on 15 of its first 20 shots. Celtics players other than Brown (who started 5-for-8 and 2-for-3 from three) combined for just one made field goal in the opening 10-plus minutes.

Momentum shifted midway through the first when Karl-Anthony Towns was called for an offensive foul on a made 3-pointer — a rarely seen call he picked up by tripping White while Towns was in the air. Kristaps Porzingis, who was moved to the bench in favor of Game 5 standout Luke Kornet, battled through visible fatigue to deliver some positive moments in the ensuing minutes, hitting a three and blocking a Towns shot to help Boston pull even at 16-16.

Then, the Celtics cratered.

Tom Thibodeau called a timeout after Porzingis’ block, and the Knicks proceeded to rip off a 17-4 run that stretched into the second quarter and gave New York its largest lead of the series to that point at 33-20. By the 5:00 mark of the second, New York had stretched that lead to 20. Miles McBride’s transition 3-pointer seconds before halftime made it 64-37 — one point shy of the largest deficit Boston had faced at any point this season.

The first half was an unmitigated disaster for Joe Mazzulla’s club. Brown had 18 points but six turnovers. The guard trio of White, Holiday and Pritchard went a combined 2-for-17 from the field and 0-for-9 from three. As a team, the Celtics shot 4-for-20 from deep and were manhandled on the boards, with New York owning a 32-18 rebounding edge at halftime.

Six different Celtics players were a minus-14 or worse over the first two quarters, with Porzingis the best of that bunch. The center, who battled symptoms from a mysterious viral illness throughout the series, did not play in the second half, finishing with four points, five rebounds and one block in 11 minutes.

Boston didn’t have a second player reach double-digit points until Al Horford hit a three with 5:07 to play in the third quarter. After the Knicks’ lead reached 41 points late in the third, Mazzulla began emptying his bench. He sent in a Torrey Craig and rookie Baylor Scheierman — the latter of whom could be in line for a larger role next season, depending on how Boston’s roster evolves in the coming months — and later inserted Xavier Tillman, Jordan Walsh, JD Davison and Neemias Queta.

Thibodeau kept most of his starters in the game until the late stages of the fourth quarter, when he finally pulled Towns, Mikal Bridges and OG Anunoby with New York leading 112-78.

As the Knicks and Pacers battle for their first NBA Finals appearances since 1999 and 2000, respectively, the Celtics’ brain trust now must choose how to proceed with their talented but aging and exorbitantly expensive core.

The Celtics have all but two of their rotation players locked up for next season (Horford and Kornet are the lone impending free agents), which typically would be a positive for a team with a roster this talented. But the price tag for those players’ 2025-26 salaries is a staggering $215.8 million. Add in the $12 million they’re set to pay their handful of deep reserves, the cost of filling out the rest of their roster with re-signings or additions, and the gigantic pile of luxury tax penalties they’d incur as a second-apron team, and next season’s Celtics are projected to cost close to $500 million, which would give them the most expensive roster in NBA history.

Now, they’ll have to contend with the fact that $54.1 million of that is going to a player in Tatum who won’t be on the court for a large portion of next season — and could miss all of it, depending on how his rehab progresses.

Changes already were coming to this roster. Players who are older (like Holiday), fragile (like Porzingis, who shot 36.1% from the field and 15.9% from three in the playoffs) or expensive for their role (like Sam Hauser) were viewed as potential offseason trade candidates even before Tatum’s injury threw the future of the franchise into flux.

Will president of basketball operations Brad Stevens attempt to keep this championship-winning group as intact as possible? Will the long-term loss of Tatum trigger an even more sweeping overhaul than the team had intended? Would the Celtics consider trading a cornerstone piece like White or even Brown, accepting an on-the-court downgrade in exchange for assets tax relief? And what influence will the team’s new Bill Chisholm-led ownership group, which is expected to have their purchase of the team approved by the NBA’s Board of Governors in June or July, have in this process?

Thanks to Friday’s no-show, Boston now must answer those franchise-shaping questions much earlier than anybody expected.