By Baxter Holmes Globe Staff
DENVER — Ball movement on offense, key stops on defense.
Those reasons, above all others, are why the Celtics won eight of nine games heading into the All-Star Break, why they were able to recover so quickly after losing their floor general, Rajon Rondo.
During that hot streak, there were in-game moments when the Celtics strayed from these principles, and each time, it cost them.
They called these moments “lessons.”
They were still able to win those games because they eventually righted themselves by reverting to their new-found formula for winning: ball movement on offense, key stops on defense.
But in their first game after a five-day layoff, the Celtics played as though they forgot how to win, forgoing their blueprint in too-long stretches that could not be overcome Tuesday.
Those reasons, above all others, are why the Celtics lost, 97-90, to the Denver Nuggets at the Pepsi Center.
“I don’t think we trusted each other at all tonight,” coach Doc Rivers said.
It was not how the Celtics wanted to begin a five-game road trip, one that heads to Los Angeles for a game against their rival, the Lakers, Wednesday.
“The good thing is, we understand how we have to play to win,” said Paul Pierce, who scored 10 points on 2-for-14 shooting.
That they were off for five days makes for a convenient culprit: The Celtics were simply out of rhythm.
“That’s the [whole] league, though,” said Kevin Garnett, who had 12 points and nine rebounds. “You come back from a long rest, you get one day to prepare for multiple games. I think your rhythm gets better as the games go, and we’re no different than that.”
The Celtics, who received season-high scoring efforts from Jeff Green (20) and Avery Bradley (17), still had a chance to steal a win against a team that coming in had won 22 of its 25 games at its home court.
Bradley tied the score with a corner 3-pointer with 5:34 left in the fourth quarter, and Denver’s sharp-shooting Danilo Gallinari untied it with a 3-pointer of his own on the next possession.
Nuggets guard Ty Lawson scored on a put-back layup, and he later hit a clutch one-handed floater just over Garnett’s outstretched hands to keep the Nuggets lead at 4.
That lead grew by a bucket after Denver’s Kenneth Farried, who grabbed 16 rebounds, scored off an offensive rebound. The Celtics fought, but this time there were no late-game heroics, no spirited comeback.
Gallinari and Lawson each had 26 points to lead the Nuggets, who also shot 20 more free throws than the Celtics.
The game-turning stretch came at the end of the third quarter, when the Nuggets turned a 65-65 score into a 78-70 lead heading into the final 12 minutes.
During that stretch, the Celtics’ offense turned to sludge. Their belief in ball movement was put on hold in favor of straight isolation.
The Nuggets picked up the few stops they needed while the Celtics tried to scrape points together to no avail.
The Celtics were gifted a 3-pointer with 1:24 in the quarter when JaVale McGee was called for goaltending a shot by Green. The ball hit the rim, bounced up, hit the backboard and seemed to be clear of the goal when McGee grabbed it, but the officials said that the ball was still in the cylinder.
That was the only break the Celtics got the rest of the way.
Rivers called timeouts to remind his team to “play with five guys” but they didn’t.
“I thought everybody really came into this game wanting to win it,” Rivers said, “and that may have gotten in our way, quite honestly. I think each guy wanted to win it instead of trusting the team.”
Late in the game, the Celtics, playing with only 10 healthy bodies, looked gassed — and that was when Denver coach George Karl told his fast-paced team to run even faster.
Karl even avoided calling a team timeout in the final 8:30 to further sap the Celtics of a potential breather in the mile-high air.
“George knows what he’s doing,” Rivers said. “He’s been around a long time.”
And so the Nuggets (34-21) were able to exact revenge after losing a triple-overtime thriller just nine days ago in Boston.
As for the Celtics, it’s this part of the season and this particular stretch that will test their mettle.
They built momentum heading into the break largely by feasting on sub-.500 teams at TD Garden, but with nine road games in 11 days, the Celtics are about to learn what kind of team they really are — and whether Tuesday’s loss was a simple slip-up owed to a long layoff or something more.