Jason Kidd and Kyrie Irving were frustrated by a "passive" performance from the Dallas Mavericks, who went down 109-97 to the Los Angeles Clippers on Sunday.

The Mavs were second best throughout the opening contest of their first-round series against the Clippers, who were without talisman Kawhi Leonard.

James Harden stepped up with 28 points in Leonard's absence, Paul George chipped in with 22 and Ivica Zubac contributed a career-high 20 points, adding 15 rebounds.

Dallas, seeded fifth, shot just 38.8 per cent for the game, and were 56-30 down by halftime.

Doncic finished with 33 points, while Irving finished with 31, but the latter was deeply frustrated by the Mavs' display.

"It really centered around the foundational point of talking about physicality and this being the playoffs," Irving said.

"A lot of guys aren't used to being here. A few young guys aren't used to being here, so they don't know what they can get away with and what the refs are going to call.

"I think this was a great first test for us. We obviously failed and we came out with a loss, but I think there are some things we can take into Game 2."

Mavs coach Kidd added: "They were physical and we were passive."

For the Clippers, it was a timely reminder of what Harden is able to offer.

"I can score with the best of 'em," Harden said.

"Still can score with the best of 'em. My role for this team is just generating really good shots and making guys' jobs easier.

"And then when my number to score is called, then you score the basketball. Obviously, Kawhi is out, so my playmaking and my volume is going to go up a little bit more, and took advantage of it."

Zubac lauded his teammate's performance, labelling Harden as "one of the greatest scorers this game has seen".

"James was great," he said. "We needed him and he played great.

"He is one of the greatest scorers this game has seen. He can do that on a nightly basis. It's just the role is different for him in this game and [with Leonard out], we need him to score more and that's what he did and we all know he can do that."

Clippers coach Tyronn Lue chipped in with the praise, too, saying: "When he's scoring the basketball and making the right play, it's huge.

"He understands that he doesn't have to do a lot of heavy lifting with Kawhi and PG both on the floor.

"But if one of those guys are out, he has to step up and be aggressive to score the basketball. That is what he has been doing for us of late. I thought he really set the tone early."