The 15

By Vinny Jace, Special to the15net dot com:

In one word, the 2025-26 Boston Celtics can be described as “confusing.” Heading into the season, the team was top-heavy, with its best player in rehab and its big-man rotation hopelessly thin. On top of that, they asked too much of their top three scorers. From Game 1 of the regular season until the fourth quarter of Game 5 in the first round of the playoffs, we collectively forgot those concerns thanks to players performing above their pay grade, excellent coaching, and championship DNA. From the first man to the last, Joe Mazzulla kept his roster ready. As players saw their roles extended, restricted, and extended again, they remained vigilant and contributed all the same. Prior to the season, the Celtics lost four critical pieces from their championship roster—including three big men and an all-around point guard—and replaced them with bargain-basement finds.

The reason the Celtics are now watching the playoffs instead of participating is that, 12 months ago, Jayson Tatum tore his Achilles tendon. The team viewed the astronomical luxury-tax bill as malpractice if left unaddressed. It was a rare moment of responsibility: essentially burning a year of contention to prepare for Tatum’s return.
Nobody—and I mean nobody—thought in the summer that Tatum would be back by March. To assume anything other than a full-season absence was laughable.

Off the back of a career year from Jaylen Brown, the Celtics exceeded expectations and outperformed their preseason win projection. By the time Tatum returned, they closed the regular season on a strong 13-3 run. Suddenly, the Celtics went from resilient but limited to legitimate title contenders. A rematch with the New York Knicks seemed inevitable.

And then the tides turned. Derrick White couldn’t throw the basketball in the ocean. Mazzulla’s reluctance to bench Sam Hauser for Payton Pritchard led to poor offensive results at the exact moment Philadelphia was discovering rhythm with a returning Joel Embiid. With no sufficient answer for how to defend Embiid, the Celtics got gashed inside and were left at the mercy of their three-point shooting—which often went cold due to a lack of offensive diversity that only became apparent recently.

Game 7’s loss confirmed that this team is in fact going backwards, and the goodwill built from the championship run is on shaky ground. Mazzulla is no longer the epic wunderkind who could turn chicken shit into chicken salad. He’s a flawed architect of a system that relies too heavily on three-point variance and its superstar. Jaylen Brown is no longer the Finals MVP and borderline First Team All-NBA player. He’s now viewed as a braggart who couldn’t cash the checks when it mattered most—never mind that he actually did so before. We have the memory of goldfish.

There are facts that cannot be ignored, even if we wish to downplay the hyperbole. Tatum’s Box Score Plus/Minus this postseason was once again over +8. While fantastic for him individually—especially considering what he went through just months earlier—it highlights a team that lacks answers beyond its star. Fans often share clips of the gravity Tatum commands, with multiple teammates left wide open. The problem over the last two years is that the Celtics have lacked the ability to make defenses pay for that over-help by attacking in the post.

Kristaps Porzingis, in 2024, filled that void even while injured for much of the playoff run. It created avenues for Boston to diversify its offense, allowed Tatum to contribute despite poor shooting, and prevented role players like White from being overtaxed. When Porzingis was sidelined, the Celtics’ offense reverted to “Mazzulla-ball”—a wrinkle that caught opponents off guard because there wasn’t 82 games of film on it. Now it’s a staple, and teams know how to cut off circulation to everyone below the top two.

The discount Boston Celtics are victims of their own success. They got so good they managed to break our hearts in the end. The 76ers are no longer the little brother. After years of stepping on rakes, they are the ones celebrating at our expense. We can console ourselves with the fact that Philadelphia’s entire project since 2013 led to this moment—their crowning achievement. Sam Hinkie tweeting a clapping GIF not because his golden goose won a championship, but because they beat a transitional Celtics team in seven games—where Boston’s best player missed the decisive contest—and they almost blew it anyway.

None of that matters now. The 76ers have the edge. The next time they come to Boston, they’ll bring an undeniable, unbearable swagger that the Celtics must destroy. Reasserting dominance after losing ground is never easy.

The core of Tatum, Brown, and White is locked in and going nowhere. The Celtics won’t do what Milwaukee did and jettison a core piece for a big name—they aren’t that desperate yet. Mazzulla is on trial with the fans, but Brad Stevens remains committed to his coach. Their cap situation remains complex, with some breathing room but not enough for radical shifts. If they nibble around the margins, stay below the luxury-tax line, and reset the repeater tax clock, they’ll be able to spend back up to the aprons in 2027 without the massive compounding penalties from 2024 and 2025.
We all hate to hear it, but 2026-27 will likely be another gap year. They may use the $27.7 million trade exception from the Anfernee Simons deal to acquire a high-level starter, along with their $15.1 million mid-level exception.

Free-agent bigs that come to mind:

•  Jusuf Nurkić

•  Sandro Mamukelashvili

•  Robert Williams

•  Nick Richards

All situational backup bigs who can do what Garza did—only better.
Trade candidates:

•  Daniel Gafford

•  Onyeka Okongwu

Also situational bigs who would likely cost draft capital and/or a player.

The free-agent pool at guard is barren, with Jevon Carter the only realistic name the Celtics might pursue.

It’s going to be a long, boring summer. Today belongs to the 76ers and their second-round opponents in New York. Hopefully, by the summer of 2027, that will have all changed.

Vinny Jace is a special contributor to The15net.com. He does not live in the past.