BOSTON – With Jayson Tatum solely in street clothes this season as he recovers from his playoff Achilles tear, empathy is limited from the Boston Celtics.

Friday night, though, might have been reason for exception, with the Heat lacking sidelined Tyler Herro, Andrew Wiggins, Davion Mitchell, Pelle Larsson and Nikola Jovic.

Through it all, with the Celtics lacking their best and the Heat missing many of their better, Friday night’s game at TD Garden still turned into another rivalry night between the teams.

At least for three quarters.

Eventually, attrition and the Celtics’ torrid late 3-point shooting took its toll for Erik Spoelstra’s team, with the Heat falling 129-116, their sixth loss in seven games.

“They had open threes that just broke the game open from there,” Spoelstra said. “But they have that kind of firepower. When they were missing threes in the first half, you always know that at any point, it can turn for them. And it did at the right moment.”

Surviving shorthanded for most of the night with offensive rebounding and 3-point shooting, time proved not to be on the Heat’s side, with Boston pulling away behind the 33 points of Derrick White and 30 of Jaylen Brown, a reminder of the potency the Celtics still retain amid Tatum’s absence.

For the Heat, there were 24 points and 14 rebounds from Kel’el Ware, who shot 6 of 7 on 3-pointers, and a solid 17-point showing from rookie Kasparas Jakucionis, that also featured six rebounds and four assists.

Of Jakucionis, Spoelstra said, “He gives us the energy, the pace. He’s fearless in terms of his playmaking, aggressiveness, getting into the paint.”

The Heat also got 16 points and 10 rebounds from Bam Adebayo and 14 points apiece form Jaime Jaquez Jr. and Norman Powell (who shot 1 of 11 on 3-pointers).

But a night after snapping a five-game winning streak with a victory over the Brooklyn Nets to open this three-game trip, fatigue and depletion provided too much. Boston closed 21 of 43 from beyond the arc.

“We’ve got to find that breakthrough moment,” Adebayo said. “Started off hot early in the season. You get these shifts throughout the season, where it feels like everything is not going your way. We have to find that breakthrough moment.”

Five Degrees of Heat from Friday night’s game:

1. Game flow: The Celtics led 30-29 after the opening period, with it tied 58-58 at halftime. From there, Boston went into the fourth up 92-89.

To that point, Spoelstra said, his team was fighting the good fight.

“I think we were something like 9 for 28 inside the circle at halftime and the game is tied. I loved where we were,” he said.

A 12-5 run to open the fourth quarter then staked the Celtics’ to the game’s first double-digit lead, at 104-94 with 9:35 to play.

With 3-pointers by White and Sam Hauser following in short order, it was 110-96 Celtics with 8:40 left.

From there, the Celtics pushed their lead to 17.

“I just thought we were playing and competing  with force, with intention and doing the things that would put ourselves in a position to win,” Spoelstra said. “And I just think the three turnovers and the four threes just derailed us. And it’s a teaching point.”

2. Super shorthanded: Playing on the second night of a back-to-back set, the Heat found themselves with only 10 available players.

The Heat departed Wednesday for the three-game trip in the absences of Larsson (ankle) and Jovic (elbow), with both remaining in South Florida.

While Herro took flight, on Friday he missed his fifth game due to a toe contusion, unlikely to make it back for Sunday night’s trip finale against the New York Knicks at Madison Square Garden.

Then, about an hour before tipoff, Wiggins was ruled out due to lower-back pain, his first absence since he missed three games in November with a hip issue.

About 30 minutes later, Mitchell was declared out due to a sprained left ankle. The only other game Mitchell had missed this season was the Dec. 6 home loss to the Sacramento Kings, due to a groin issue.

“They have different issues,” Spoelstra said of Wiggins and Mitchell. “Davion was warming up to see how he felt. It just wasn’t good enough. I had that feeling with both of them in the walkthrough today. With the back with Wiggs, you just have to see how he responds.”

3. Lineup shuffle: That had the Heat opening with their 12th lineup in their 28 games, one that included Jakucionis, a night after he received his first rotation minutes of the season, a night after he scored his first NBA points.

“It happened fast,” Jakucionis said of his sudden injection into the mix. “You never know when the chance is coming. When D-Mitch was out, I just have to be ready every time they need me and I’m trying to stay ready every time they need me.”

The new lineup was rounded out by Ware, Adebayo, Powell and Jaquez, in his first start of the season.

That, in turn, left the Heat with an available bench of only Dru Smith, Simone Fontecchio, Keshad Johnson and two-way players Myron Gardner and Vlad Goldin.

Gardner received his first extended action with the team, having played a total of nine minutes over four appearances prior to Friday night.

In addition to the ailing players, also away from the Heat on Friday were guard Terry Rozier, due to his NBA-imposed leave of absence, and two-way guard Jahmir Young, who is on G League assignment.

4. More Ware: Starting for the second consecutive night, Ware picked up where he left off with Thursday night’s 22 points and 12 rebounds in Brooklyn, this time with 10 points and five rebounds in his opening 8:33 stint.

“I’m more comfortable out there,” he said, “Playing through the game, playing through the flow.”

Becoming a constant in Ware’s play is his 3-point shooting, again left largely unguarded at the arc by unknowing opponents.

“I feel like I was in a rhythm and feel comfortable just letting it go,” he said.

Also, Ware extended his career-best streak of games with at least one blocked shot to 11.

5. Welcome back Simone: Entering amid a miserable months-long slump, Fontecchio provided relief scoring with three early 3-pointers.

When Fontecchio hit his third 3-pointer midway through the second period, it was just the second time since Nov. 19 he had converted as many as three in a game.

Fontecchio’s four 3-pointers were one shy of his season high.