BOSTON — The shorthanded Celtics ran out of gas on Friday night, squandering a 22-point lead to the Cavaliers despite monster offensive performances from Jayson Tatum (46 points)and Jaylen Brown (37 points). Donovan Mitchell (41 points) and Evan Mobley (11 points, 8 rebounds in fourth quarter) bested that duo late though, helping the Cavs close the door on the comeback with a 28-18 advantage in the final frame.

Boston’s lackluster performance late can be blamed on a variety of factors. Sam Hauser (38 minutes) was abused regularly by the Cavs star guards on switches. Boston’s rebounding (seven offensive rebounds allowed in fourth) was a huge weak spot. However, one key adjustment by Kenny Atkinson may have unlocked the Cavs’ best chance of taking down Boston in a seemingly inevitable playoff showdown awaiting in the East Finals.

All year long, the Cavs have leaned on their double bigs for an advantage for most matchups. However, that tactic was not going well against the Celtics for most of the first three quarters as Jayson Tatum was regularly abused Jarrett Allen in switches.

However, the Cavs made a key adjustment, electing to bench starting center Jarrett Allen for the entire fourth quarter. Mobley played as the sole big for eight minutes and then Cleveland just went with no bigs entirely for four fourth quarter creating a host of matchup adjustments for Boston.

Offensively, Boston’s stars did not have an easy target for mismatches anymore with a host of wings on the floor along with Mobley. The addition of De’Andre Hunter at the trade deadline enabled them to pull off this tactic a bit easier with solid versatility across the board.

The tweak also created a big edge for the Cavs offensively against a weary Celtics defense. They found weak spots to attack (Sam Hauser, Al Horford) in mismatches and crushed the offensive glass (seven offensive boards) in the fourth quarter as a fatigued short rotation for Boston failed to keep Cleveland away from crash opportunities.

Brown made note of the change after the loss and the impact it had.

“Yeah, it’s a game within a game,” Brown said. “To start the game, they started off double big with Allen and Mobley. To finish the game, they went away from Allen and put Mobley at the five. So that changed the game a little bit, but it allows you to get to the basket, etc.

“In the second half, they went more Dean Wade I guess to try to match up physically, get some stops. But we’ve got to be able to recognize, space the floor and being able to get to where we need to get to. So in the game, we’ve got to make adjustments. I thought they did a good job of adjusting, and I thought we could have did a better job of adjusting to them.”

The return of Kristaps Porzingis and Jrue Holiday would have helped in some areas for Boston but the Cavs are still a very challenging team to guard in this alignment. The Celtics had no one who could stay in front of Mitchell (26 points in second half) and the Cavs have shooting all over the perimeter when Allen sits.

“We changed up our coverages and you saw we changed the matchup,” Kenny Atkinson said after the win. “I don’t know if that’s the reason. Sometimes it’s we’re playing a little harder, a little smarter, contesting a little better, rebounding a little better. So maybe the matchup change and coverage change had a little to do with it.”

Ultimately, these are the lineups that will put Boston to the test and Joe Mazzulla had no answer for it on Friday night as his shorthanded roster ran out of gas. The challenge will remain big next time come a postseason series and Boston’s supporting cast will need to do a better job of punishing Cleveland’s downsizing in order to keep pace offensively.

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