CelticsNBANBA 2026-27 Preseason PreviewsNBA East

Boston Celtics 2026-27 NBA Preseason Preview

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Sep 28, 2026; Boston, MA, USA; Boston Celtics forward/guard Jayson Tatum (0) with forward Paul George (13) during media day at Auerbach Center. Mandatory Credit: David Butler II-Imagn Images
Credit: David Butler II-Imagn Images
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The Boston Celtics’ front office is under a microscope following a volatile past year.

Boston went from an expected gap year with Jayson Tatum’s return unknown, to a theoretical championship contender when he returned, to an embarrassing first-round collapse.

After two consecutive early playoff exits, Celtics president of basketball operations Brad Stevens decided a dramatic change was necessary. Boston is building its future around Tatum, hoping he returns to First Team All-NBA form.

The supporting cast around Tatum provides complementary skills that should help the Celtics build their new long-term identity. The 2026-27 season offers an exciting outlook for the Celtics’ future, but it also sets up a high-pressure year for the entire cast if they fail to meet expectations.

Team’s Biggest Offseason Loss: Jaylen Brown

No player’s exit this offseason is more notable than Jaylen Brown’s. After 10 winning-filled seasons, Boston bid farewell to an infrastructure built around The Jays.

Advanced analytics purists may argue that the Celtics are actually better without Brown. Over the last five seasons, including both the regular season and the playoffs, Boston has a better net rating with Brown off the floor (+11.8) than on (+7.4).

On/Off data via DataBallr

In fact, the Celtics have had a negative net rating with Brown on the court and Tatum off the court across the past five postseasons (-3.7).

On/Off data via DataBallr

Analytics are a great tool, but don’t tell the full story. For example, the Celtics were even statistically better this past year with Brown off the court than on. However, stats on paper can’t capture the human elements of the game.

The main goal of basketball is to score more points than your opponent. Brown led the NBA in total field goals made. His reliability as a scorer lightened the burden for his teammates and forced the opposition to spend time and attention slowing him down, creating more opportunities for others. The Celtics played well in games without Brown against lesser competition, but if he had been removed from the roster for all 82 games, Boston’s offense would have suffered significantly without their go-to scorer.

Shot creation is the most valuable skill in basketball, and Brown excelled at it at high volume. Tatum will replace Brown in that role. However, it still leaves the Celtics with one proven volume scorer, and others who will need to step up if they want to be taken seriously as championship contenders.

Team’s Biggest Offseason Addition: Mitchell Robinson

Getting a full season of Tatum is hands down the Celtics’ biggest addition. However, among the players they transactionally acquired during the 2026 offseason, Mitchell Robinson solidifies Boston’s center rotation.

In 2025, when the Celtics and Knicks met in the Eastern Conference Semifinals, Robinson posted a series-high +18.1 net rating. His impact on the glass and on defense was tremendous.

Boston heavily emphasized rebounding last season, especially on offense. Robinson fits perfectly into that philosophy as not only the reigning leader in offensive rebounding rate last season, but also the NBA’s all-time playoff leader in offensive rebounds per 100 possessions, according to Basketball Reference.

Joel Embiid pushed the Celtics’ frontcourt around during their playoff exit, so Robinson’s strength will be a much-needed asset in the 2027 postseason. Stealing him from a division rival in the New York Knicks is just the cherry on top.

Celtics’ Best-Case Scenario Outcome

Stevens, as he did last year, refuses to put a ceiling on his team. Does that mean a championship push is in the cards for the Celtics? Stevens certainly isn’t ruling it out.

He and head coach Joe Mazzulla seem to be honing in on the style of basketball they want to play moving forward: generating high-quality threes, winning the shot margin, and playing complementary basketball.

Any championship contention would, of course, require Tatum to return to his top-five form. He recovered from an Achilles tear in nine months to average 21.8 points, 5.3 assists, and a career-high 10.0 rebounds per game. It’s hard to imagine that he came back all the way just to let up in the offseason; expect Tatum to return to full strength next season.​

Which Celtics Need to Step Up?

White and Pritchard made important strides as playmakers last season, but without Brown’s shot creation, they will now be relied upon as prominent scorers as well. That shines a particularly bright light on White, who shot just 39.4% from the field last season with a -4.9% relative true shooting mark. The Celtics proved they could succeed in the regular season despite his shooting inefficiency. Still, for them to be taken seriously as contenders, and for White to remain worth his lucrative contract (over 15 percent of the salary cap), he needs to prove last year wasn’t the sign of oncoming regression.

With Robinson’s addition, Boston’s front court is much better positioned. He and Neemias Queta provide strong rim protection, rebounding prowess, and lob threats on the offensive end.

With Tatum replacing Brown in the lone-superstar system, a stronger front court, and continued development from the supporting cast that helped Boston overachieve last season, the Celtics should take another step forward in their post-2024 retooling. If Paul George can contribute at the level he did with the Philadelphia 76ers against Boston in the first round, the Celtics could become truly dangerous.

Another 50-plus win season and a top-four seed should begin the conversation for this season’s goals. But with Stevens saying there is no ceiling on the group, then Banner 19 should be considered on the table.

Celtics’ Worst-Case Scenario Outcome

The Celtics proved that their floor is high last season, and they should keep improving under the new philosophy Mazzulla is establishing.

However, an underdiscussed factor from last season’s unexpected success was their good fortune with injuries. Aside from Tatum’s absence, none of their key players missed significant time for injury. Trade deadline acquisition Nikola Vucevic suffered a fractured finger that sidelined him for about a month ahead of the playoffs, which stunted growth in Boston’s system. Other than that, all of their expected contributors were healthy.

Now, three of their biggest x-factors for the coming season have questions about their availability. Tatum, for as aggressively as he’s attacked his rehab, suffered a notoriously major injury not even 18 months ago. Boston’s trade of Brown suggests they feel optimistic about his recovery, but still, until he delivers a season’s worth of play, questions about his durability will linger.

Is Boston Set Up to Stay Healthy?

The Celtics’ other two big offseason additions come with availability concerns as well. Robinson appeared in 60 games last season for the first time in the last five seasons. George has reached 60 games played in a year only once in the past seven seasons.”We were also 3-11 against the top-three seeds in the West and the other top-two in the East. So we have to get better.”

Playing the injury-risk card as a worst-case scenario is low-hanging fruit, but it’s a relevant conversation given the injury history of the three players expected to elevate the group from last season.

Along with a seemingly improved Eastern Conference around them and a new draft lottery system that disincentivizes tanking, the schedule ahead looks tougher. The Celtics struggled against With more conference opponents expected to push for playoff contention, and more notable injury histories among their key players, the Celtics could find themselves fighting off up-and-comers for playoff positioning if Tatum or any other key contributors miss significant time.

Celtics’ Biggest Question Heading Into 2026-27 Season

Which of the Celtics’ youth core can establish themselves as long-term building blocks?

While the team’s focus is on the upcoming season, Boston’s front office traded Brown to create future optionality. Stevens opted against spending big to acquire Giannis Antetokounmpo in the offseason, and instead maximize their assets moving forward.

The Celtics will likely use some of their youth in the years to come by making trades that make them higher-level contenders. In the meantime, those players will get opportunities to prove they can make an impact for Boston’s next championship team.

Because Hugo Gonzalez and Baylor Scheierman’s names were attached to the Giannis rumors, they will be at the top of the list of players the Celtics are evaluating internally.

Jordan Walsh and Ron Harper Jr. enjoyed breakout seasons that resulted in contract extensions from Boston this summer.

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Written by
TJ Mabardy - Content Developer

TJ is a Content Developer for The Lead, where he helps oversee content production for Boston sports and broader NFL and NBA coverage. Formerly wrote for FanSided's Chowder & Champions. Quinnipiac University class of 2023.

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