THE FINAL SECONDS ticked off the Game 7 clock as the Boston Celtics suffered through a heartbreaking dose of déjà vu.

For a second straight season, Boston was home to a championship celebration — for the opposing team. In June 2022, it was the Golden State Warriors who hoisted the Larry O’Brien Trophy on the TD Garden parquet floor after a title-clinching Game 6 win.

In late May this year, it was the Miami Heat, who for the second time in four years had prevented the Celtics from reaching the Finals, stopping Boston’s bid to become the first NBA team to win a seven-game series after trailing 3-0 in the Eastern Conference finals.

“We know we had a special opportunity this year. We just fell a little bit short,” Celtics All-NBA forward Jayson Tatum said after that Game 7 loss to Miami. “It’s not like we’re not capable [or] don’t have the talent.

“We do.”

The Celtics have been one of the league’s most talented teams for years. Since the start of the 2016-17 season, Boston has won more playoff games (61) than every team but the Warriors and more regular-season games (349) than all but the Milwaukee Bucks, according to ESPN Stats & Information research.

The Celtics have played 112 playoff games over those seven seasons, the product of several deep, grueling postseason runs, including four conference finals appearances and the 2022 Finals.

But no team in NBA history has appeared in more playoff games over a seven-season span without winning a championship. To help remedy that, Boston took two of the biggest swings of the offseason.

In June, the Celtics acquired stretch big man Kristaps Porzingis in a three-team deal that also sent former Defensive Player of the Year Marcus Smart — who doubled as Boston’s longest-tenured player — to the Memphis Grizzlies. Then, on the day before training camp began, Boston landed Jrue Holiday from the Portland Trail Blazers, just days after he had landed there as part of Milwaukee’s move to acquire Damian Lillard.

The moves have given Boston unparalleled flexibility at both ends of the court, giving coach Joe Mazzulla a top-six rotation that provides elite floor spacing — and alternative options in late-game situations — while not sacrificing anything defensively.

Those moves also reflected the reality that, thanks to the challenges presented by the league’s new collective bargaining agreement, the Celtics’ time to strike is now.

“There’s a lot of excitement,” Derrick White told ESPN. “Adding Jrue and KP, and how close we’ve been every year since I’ve been here … a championship is what we’re focusing on.”

THE CELTICS ARE rushing toward a massive fiscal cliff.

The new CBA created several onerous restrictions on teams at the top end of the spending scale — none more so than the much-discussed “second apron” above the luxury tax, which will heavily penalize teams that exceed it.

The rule was designed, in large part, to rein in the excesses of teams such as the Warriors and LA Clippers that have ventured deep into the luxury tax. But it was also designed to make it difficult for a team sitting at the top of the league to remain there for an extended period without having to make very difficult choices.

For Boston, those choices are rapidly approaching.

“All of those discussions have been endless since the new CBA came out,” Celtics president of basketball operations Brad Stevens said on media day. “Those are things that we’ve hashed back and forth … and have prepared [us] for any scenario.”

All of those scenarios involve gaming out what Boston will do once supermax extensions for Jaylen Brown and Tatum have kicked in, beginning with the 2025-26 season.