INDIANAPOLIS – Bad has gotten worse for a team now suddenly defenseless and facing a postseason that will start at the bottom of the Eastern Conference play-in bracket.

With every reason to play for – against a team with none – the Heat fell for the seventh time in their last eight games with a 125-118 loss Sunday night to the league-worst Indiana Pacers at Gainbridge Fieldhouse, a team that had lost 18 of its previous 19 games.

Having already lost to the Pacers in blowout fashion in their previous visit, one would have thought that would have been a lesson learned.

It was not, with the Heat at defensive depths practically unfathomable for a team in a fight for play-in seeding, now with seven games remaining in what is turning into a regrettable regular season.

This one came after giving up a franchise-record 149 points in Friday night’s loss to the Cleveland Cavaliers.

“What I do know about our locker room,” coach Erik Spoelstra said, “is our guys really want this. I know these last two games, it does not appear that way. And the five losses before that, particularly on the defensive end, we can’t explain it right now.”

Needing something manageable on the final stop of a three-game trip and the first night of a back-to-back set that concludes Monday night against the Philadelphia 76ers, the Heat instead found themselves desperate and again lacking, while playing in the absence of Norman Powell.

The Heat clinched at least a play-in berth on Saturday night, with their postseason ticket punched with a Milwaukee Bucks loss. The way it is looking at the moment, it could wind up being a one-and-done postseason.

Tyler Herro, who kept the Heat in reach early with his offense, led the Heat with 31 points, supported by 17 from Jaime Jaquez Jr, 15 from Pelle Larsson and 15 from Andrew Wiggins. The Heat also got a 15-point, 12-rebound double-double from Bam Adebayo.

Nonetheless, the Heat scored just 11 points in the decisive fourth quarter.

We’re all uncomfortable about this.

(“We’re disappointed, we’re upset, we’re angry,” Spoelstra said. “It’s every single emotion you can go through.”

Despite two fouls in the opening minutes, Pascal Siakam led the Pacers with 30 points.

Five Degrees of Heat from Friday night’s game:

1. Game flow: The Heat led 36-34 after the first period, with the Pacers then taking a 79-75 lead into the intermission, a game after the Heat allowed an 81-point first half on Thursday night in Cleveland.

“Sometimes that just happens over the course of a long season,” Spoelstra said of the Heat losing their way defensively. “It’s happening at the wrong time for us right now.”

Indiana then went into the fourth quarter up 108-107, with the Heat entering the night 2-28 this season when trailing after the third quarter, including 1-17 on the road.

From there, the Pacers moved to an 11-point lead with 3:22 to play on a sequence that included a technical foul on Heat guard Davion Mitchell for arguing a foul call.

“The basket opened up for them,” Mitchell said. “Obviously, I think we just gave them confidence at the beginning.”

But, Adebayo said, still hope until potentially being eliminated from a direct ticket to the playoffs.

“I get that at least we’re in the play-in,” he said, “but nobody wants to be in that. So for us, we really gotta bubble down.”

2. No Norm: With Powell missing his 20th game, the  Heat returned to a lineup of Herro, Adebayo, Larsson, Wiggins and Mitchell.

That group entered 3-3, with it Larsson’s 49th start.

Powell’s absence also got Simone Fontecchio back in the rotation.

The Pacers opened with the eclectic starting lineup of Andrew Nembhard, Quenton Jackson, Ethan Thompson, Jalen Slawson and Pascal Siakam.

Thompson began the season with the Heat’s G League team, after spending training camp with the Heat. Also in the Pacers’ rotation was former Heat summer and G League prospect Micah Potter, who scored 19 in the first half on 5 of 6 on 3-pointers.

It was the Pacers’ 42nd starting lineup of the season. The Heat, by contrast, have utilized 25.

3. Herro ball: With Powell out and thereby little need to defer on the wing, Herro scored 16 points in the first quarter on 7-of-11 shooting, then up to 23 by the intermission,

It was a bounce-back game of sorts for Herro, who was coming off an 11-point performance in Friday night’s blowout loss in Cleveland, his first game with 20 or more in his last four outings.

Herro was up to 31 points through three quarters, before stalling out like the entire Heat offense in the fourth.

“We gotta stay the course, obviously we’re not in a position we want to be in,” Herro said. “We can’t give up on the season, there’s seven games left.  We’re getting in this play-in either way.”

4. Jaquez hits 1,000: With his 14th point, which came on a 3-pointer with 5.3 seconds left in the first half, Jaquez became the fourth Heat player to score 1,000 points off the bench in a season, joining Herro, Dwyane Wade and Tyler Johnson.

Jaquez had 15 at the intermission, joining Herro as the only Heat players with more than nine over the opening two periods.

5. Challenge looms: Up is Monday night’s completion of the back-to-back set, the home game against the 76ers, who are listing Joel Embiid, Tyrese Maxey, Paul George and VJ Edgecombe as all being available.

The game against a 76ers team that was idle Sunday will decide the potentially critical tiebreaker in the three-game head-to-head series.

“We’re gonna take this L, take that last L against Cleveland,” Spoelstra said. “They’re two very disappointing losses. And we’re gonna go back to Miami and figure out how to get this one tomorrow. That’s our only focus right now. We know what it is, we know what we have to do.”