Celtics humbled by Mavs in missed opportunity to sweep: ‘We have to reassemble’

DALLAS – Forget the history, which says the Boston Celtics won this series after capturing the first three games. At some point, an NBA team will come back from such a deficit. The Celtics should know that after nearly pulling off the feat last season.

If they felt too comfortable entering Friday night’s Game 4 of the NBA Finals, they should recognize the need to locate some urgency again after falling to the Dallas Mavericks in a 122-84 blowout. Everything that went right for the Celtics over the first three games disintegrated in the fourth, leading Boston to need some garbage-time buckets just to avoid the largest loss in finals history.

There’s real pressure now on the Celtics to take Game 5 at home. If they don’t, they will need to return to Dallas for Game 6, and if they lose that, who knows what would happen in a Game 7 against Luka Dončić and Kyrie Irving. That message might sound like it comes straight from Kevin Millar’s mouth, but the Celtics should now have an appreciation for everything it will take to close out the Mavericks.

“We don’t dismiss it,” Jaylen Brown said of the loss. “We’re going to learn from it. We’re going to see how and why, exactly where the game was won and lost. And then we take those experiences and then we come out and we play like our life depends on it. Because it does.”

The Celtics controlled the first three games of the series with a show of physicality and discipline. As soon as they let up, the details of the matchup flipped. The Mavericks supporting cast, silent earlier in the series, stepped up, with Dereck Lively and Dante Exum starring in their roles. Jason Kidd asked pregame for the Dallas players to maintain their pace throughout the game after he thought they slowed down over the latter part of the first three contests. The Celtics couldn’t even force Dončić and Irving to step onto the court in the fourth quarter, never mind wear on them enough to make a difference. The two stars combined to score 50 points on 22-of-44 shooting even though they both checked out for good near the end of the third.

With a 3-1 series lead, the Celtics are still in charge of the NBA Finals. But a series can shift quickly. They should have an appropriate fear of what Dallas can do at its best.

“These are the moments that can make you or break you,” Brown said. “We have to reassemble. We have to look at it and learn from it, and then we’ve got to embrace it and attack it. It’s going to be hard to do what we’re trying to do. We didn’t expect anything to be easy, but it’s no reason to lose our head. Tip your cap to Dallas. They came out and played well, and we’ve just got to be better on the next one.”

Much better. As Al Horford put it, the Celtics “didn’t really make any adjustments” over the first three games. Their game plan worked to take away the Mavericks’ 3-point attempts, eliminate their alley-oops and work Dončić to the point of fatigue. It took three-plus games for the Celtics to need anything but Plan A, but they switched strategies late in the first quarter by downsizing to a lineup with Jayson Tatum at center. It seemed to be an acknowledgment from the coaching staff that their first option, using Xavier Tillman as Al Horford’s only backup, as they did throughout Game 3, might not cut it. Not with the Mavericks having success hunting Tillman on switches and the Boston offense suffering from the way Tillman cramps its spacing.

The Celtics did use Tatum at center at times during the regular season, but very rarely. They were outscored by five points over two minutes with him at the position before turning back to Tillman. For the first time in the series, really, the Mavericks forced the Celtics to reexamine some choices. The Boston offense never found answers while finishing with its second-worst field goal percentage of the entire season – without the extended garbage time, it would have been the worst. The Celtics scored a season-low 26 points in the paint and also saw their usually large 3-point attempt advantage shrink to plus-four.

“They did a great job flying around, making indecision on whether to shoot it or drive, and their multiple efforts,” Joe Mazzulla said. “And I thought their five men did a great job protecting the paint. Whenever we went in for a layup, they had multiple guys contesting. I thought they did a great job flying around on the defensive end.”

Boston found ways to tear apart Dallas’ identity over the first three games, but Friday night showed what the Mavericks can be. Their athletic supporting cast, rim protection and two-star attack all stood out, as they did during the team’s march through the Western Conference. The Celtics couldn’t dictate the terms of play like they did earlier in the series. As evidenced by the toggling back and forth between Tatum and Tillman at center, they missed the presence of Kristaps Porziņģis. He appeared to move pretty well during a pregame warmup but was “not quite there” physically, according to Mazzulla. Though Tillman played well in Game 3, Dallas’ size and shot blocking can punish a lack of floor spacing.

“I think this is the most stagnant that we’ve been this series and the worst job of owning our space on the offensive end and doing what we wanted to do instead of what they were forcing us to do,” Tatum said. “And, you know, we did a great job of that in the first three games, and this one, we didn’t.”

Earlier Friday, while most of the American Airlines Center was quiet, the Larry O’Brien Trophy presentation could be heard booming through the arena loudspeakers. It wasn’t the real ceremony, of course, but such things require a dress rehearsal. So, hours before Game 4, the broadcast team practiced giving the Celtics the championship.

They won’t be handed such a present in the actual NBA Finals. To walk out of the series with the Larry O’Brien Trophy, they will need to earn it. They certainly didn’t do that Friday. Mazzulla pulled the Boston starters with 3:18 left in the third quarter, already looking ahead to the rest of the series with an 88-52 deficit.

For the final 15 minutes and change, Tatum sat at the end of the Boston bench. In some ways, he was still in the same place he began the night, one win away from his first championship. Still, with the Game 4 debacle all but over, that title must have felt a little further away.

The Celtics should understand the gravity of Game 5. It won’t be win or else, but it will be win or ugh.

“The one thing I can tell you about our group is that time and time again, we’ve responded any time we have adversity,” Horford said. “And this is an opportunity that we have here in front of us.”