DALLAS -- The home crowd loudly booed at the American Airlines Center during a timeout midway through the third quarter Friday night, when the Dallas Mavericks trailed the Charlotte Hornets by 18 points.

"We probably should have been booed in the first quarter," Mavericks coach Jason Kidd said after a 117-109 loss to an undermanned Charlotte team that dropped Dallas (36-38) to 11th place in the Western Conference standings, a spot out of the play-in scenario.

Kidd described the Mavs' effort as "awful" and "dog s---" in the first quarter, when the 24-51 Hornets scored 37 points despite missing three starters and playing on the second night of a back-to-back.

"The interest level wasn't high," Kidd said. "It was just disappointing."

Dallas entered the game as a 16-point favorite, making this the biggest upset in the NBA this season, according to ESPN Stats & Information.

The Mavs' only lead of the game occurred after Luka Doncic drove for a floater after the opening possession. The Hornets led by as many as 21 points before Dallas rallied in the fourth quarter, cutting the deficit to one with 8:30 remaining, only for Charlotte to immediately respond with a 10-0 run.

Dallas is 7-12 since All-Star guard Kyrie Irving joined the team following a blockbuster trade with the Brooklyn Nets that Mavs management hoped would boost their chances to contend this season. That includes 3-7 when Irving and Doncic, who have both dealt with nagging injuries, are in the starting lineup together.

"We got to fight hard, play harder," said Doncic, who had 34 points, 10 rebounds and eight assists in his second outing since returning from a five-game absence due to a left thigh strain. "That's about it. We got to show we care and it starts with me first. I've just got to lead this team, being better, playing harder. It's on me."

Doncic, who was fined $35,000 by the NBA earlier in the day for making a money-sign gesture toward referees late in Wednesday's protested loss to the Golden State Warriors, acknowledged that he is as frustrated as he's been during his five-year career.

"I think you can see it with me on the court," Doncic said. "Sometimes I don't feel it's me. I'm just being out there. I used to have really fun, smiling on court, but it's just been so frustrating for a lot of reasons, not just basketball."

Asked what else was bothering him, Doncic cited issues in his private life.

Irving scoffed at what he called "the pretty words that sports loves to put in, like hope and concern," saying that an adjustment period was anticipated after a major midseason trade. The injuries to Doncic and Irving, who has missed a total of four games due to right foot soreness, have complicated that process.

Nevertheless, Irving attributed the Mavs' poor start against the Hornets to a lack of energy.

"We're a very poised group on days where I feel like we put in the best effort, and then on days where kind of the energy falters or we don't start off well or the offense isn't going or people aren't making shots, there could be some emotional pulling in other directions that can dictate the outcome of games," said Irving, who had 18 points, nine rebounds and seven assists but shot poorly (6 of 16 from the floor, including 1 of 8 from 3-point range).

"I've been in New York City, so I know what that's like. You obviously want to play well, but it's only five people on the court that can play for the Dallas Mavericks. If the fans wanna change places, then hey, be my guest. Got years of work ahead to be great enough to be on this level."

Kyrie Irving

"And we're still feeling each other out in a way of getting used to each other's efforts and attitudes and temperament. And that's a real thing. That's a human thing. That's a human element. Whether people believe it in basketball or not, there's a very fine line between winning basketball games and everyone being on the same page and losing basketball games and things splintering and pointing fingers."

As much as Kidd considered the boos deserved, Irving considered the fans' reaction to be irrelevant.

"So? So what? Just the way I feel about it," Irving said. "I've been in New York City, so I know what that's like. You obviously want to play well, but it's only five people on the court that can play for the Dallas Mavericks. If the fans want to change places, then hey, be my guest. Got years of work ahead to be great enough to be on this level. But our focus isn't necessarily on the boos. It should be on our performance and just being there for each other."