LAS VEGAS — The plan for the Lakers had been to turn their fourth preseason game into a dress rehearsal for the upcoming season.

But that was not the case.

The Lakers did get the preseason debut of center Walker Kessler on Tuesday night, a good sign for them to see their biggest offseason acquisition play.

But on the flip side, Luka Doncic didn’t play in the Lakers’ 101-89 loss to the Golden State Warriors at T-Mobile Arena because he was resting.

“He’s not injured, just getting the night off,” Lakers coach JJ Redick said.

So, it was left up to Kessler, Austin Reaves and the rest of the available Lakers to sort things out. And Reaves and Kessler were on point.

In just his second preseason game, Reaves was doing what is expected of him, scoring 28 points on 10-for-18 shooting, including four for seven on three-pointers, with seven assists and four rebounds. But forced to handle the ball more with Doncic out, Reaves also had seven turnovers.

Kessler started and had 11 points, nine rebounds, one blocked shot and one steal in 16 minutes.

For the Lakers, it was good to see Kessler on the court. They gave up a lot to acquire him in a trade with the Utah Jazz — two unprotected first-round picks and two pick swaps — and then signed him to a four-year, $130-million contract.

Kessler played only five games last season while recovering from a torn labrum in his left shoulder. He missed the first three Lakers preseason games because of a left pinky injury.

Kessler yearned to play again.

“It was a lot of fun being out there again,” he said. “It’s been so long. Before the game, I was actually pretty nervous, to be honest. But, getting out there and just playing with the guys, it was a blast. ... I think I have a certain presence on the floor, but I think my teammates around me did a great job of playing defense on the perimeter. I think we shared the ball really well tonight. Just how it was, especially in the first half. It was a lot of fun.”

He began his night with a defensive rebound, which allowed the Lakers to set up their offense early in the first quarter.

Kessler then cut to the basket, took a pass from Reaves and scored on a layup, his first points of the preseason.

His second basket was a left-handed layup early in the second quarter. Shortly after, Kessler blocked a shot by Warriors center Charles Bassey from behind, a display of his defensive presence.

Another good sign, less than a minute later, was when Kessler got an offensive rebound and bounded back up for a dunk.

When the Warriors went to their small-ball lineup in the first quarter, it meant the 7-foot-2 Kessler would be tested on defense, because his man was 6-2 Gary Payton II. It meant Kessler was forced to play defense on the perimeter and not down low where the Lakers prefer him.

Still, Kessler held his own.

(David Becker / AP)

While he was unable to play, Kessler learned a few things about himself.

“What I missed most was competing,” Kessler said. “Quite frankly, competing to win, and I think as far as making me a better basketball player, I just think it has made me long to go try to win every game and win every night. So returning, I think it makes me a little better basketball player.”

The Lakers lost to the Warriors for the second time this preseason. Their other two games were victories over the Sacramento Kings. They play one more preseason game, Friday night against the Denver Nuggets at Crypto.com Arena, and then open the season against the Warriors at home on Oct. 21.

Before the game, Redick said the plan was for the Lakers to “continue to work on us.”

“We have kind of circled this game, not as a full dress rehearsal, just in terms of our scout presentation, but we gave the guys a sample of that this morning and at shootaround,” Redick said. “Not as much game-planning necessarily, but just kind of the sequencing of how we present prior to a game. We’ll do the same thing pregame with a brief personnel tape. We just want to get better. I mean, that’s the biggest thing. We want to get healthy, we want to get better, we want to continue to build our fitness and cardio level and find a rhythm. And it’s been a little disjointed with having some guys out.”

Redick said rookie Cameron Carr (undisclosed), guard Collin Sexton (lower leg) and forwards Ziaire Williams (right foot contusion) and Adou Thiero (undisclosed) are still day to day with their injuries.