INDIANAPOLIS — The bloom is off the rose with the new starting lineup.

Knicks coach Tom Thibodeau ran back the reworked starting unit he used in Game 3 — inserting Mitchell Robinson in place of Josh Hart.

But this time around, it produced rough results in a 130-121 Game 4 loss to the Pacers on Tuesday night at Gainbridge Fieldhouse.

That unit fell behind 16-11 to start the game before Karl-Anthony Towns subbed out with 7:48 left in the first quarter after picking up his second foul.

Then when the unit was back on the floor together to start the third quarter, they gave up an immediate 7-0 run to fall behind by 12 points.

The Knicks entered halftime trailing by five, and when Robinson came out for Hart with 5:55 left in the third quarter, they trailed by eight.

“There’s obviously some good, but also things we have to do a lot better,” Thibodeau said of the unit. “I don’t think we had a good grouping. … We start the third without great energy, and you can’t do that. Once it gets to double figures, now they’ve got more confidence. We gotta make sure we play with the proper approach and intensity and force and be connected.”

In Game 3, the starting unit was plus-1. But Robinson’s struggles on Tuesday meant the group was not nearly as effective this time around.

He was a team-worst minus-20.

He did not play at all in the fourth quarter, with Thibodeau opting to go with Hart instead until he fouled out.

“I’m going to start off with myself,” Robinson said. “Feel like I got off to a slow start, especially in the first half. Started to pick it up in the second. I can’t allow that, especially at the time right now. Just got to be better from the jump.”

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The starters’ woes have hovered over the Knicks the whole postseason. Thibodeau’s change reaped rewards for one game.

But Tuesday night, the problem came roaring back.