LAIE, Hawaii – Yaxel Lendeborg could not believe how open he was.

The 6-foot-9 forward enjoyed only one chance to play with Steph Curry and Draymond Green during the Warriors’ get-together last week at Jimmy Butler’s San Diego abode.

That was all it took for the rookie to receive a sampling of what life on the court could look like in his first year in the NBA.

Curry screened Lendeborg’s defender on an out-of-bounds play and then raced to the perimeter for a shot. As the defense shifted in Curry’s direction, Green fired a pass to an unattended Lendeborg.

“I’ve never come off of a back screen and seen nobody in front of me or behind me, so yeah, it was ridiculous,” Lendeborg recalled on Monday at the Warriors’ media day event.

He dunked it.

The vets loved it.

They let him know.

“That’s all year! All year,” Green and Curry told the rookie.

That moment added another chapter to what has been a storybook past six months for Lendeborg.

A national championship as the star at Michigan. Being drafted No. 11 overall by one of the NBA’s premier franchises. Leading the Warriors’ youngsters to their first Las Vegas summer league title since 2013.

“He’s obviously a winner,” Curry said on Tuesday afternoon. “You can’t have that success he had in college and that big role he had without that mentality.”

From Andre Iguodala, to Harrison Barnes, to Kevin Durant, to Andrew Wiggins and Jimmy Butler, the Warriors have a consistent history of featuring small forwards who thrive in a do-it-all capacity.

Lendeborg certainly doesn’t lack the confidence that he could be next.

“I feel like I could win Rookie of the Year,” Lendeborg said, before adding, “But that’s not my main focus.”

Lendeborg’s springtime and summer successes seemed to indicate he is next in line.

But the run of trophy-lifting did not convince the 24-year-old that he had arrived. Instead, it revealed weaknesses.

In Las Vegas, Lendeborg had huffed and puffed through games. Offensive domination segued into lackadaisical defensive possessions, the forward sometimes jogging when the moment required a sprint.

He had admitted to taking time to celebrate after leading Michigan to a title, and he was paying for it in the desert. Once the exhibitions were over, Lendeborg vowed he would never endure that sort of fatigue again.

“I’ve always been the kind of person that you would have to tell to get into the gym,” Lendeborg said. “But now that it’s kind of reversed, it’s like I’m in the NBA now; I’m a rookie. I’ve got to make a name for myself here.”

Having gone from reluctant participant to unabashed gym rat, even his coach is concerned about burnout.

“I’ve literally had three different conversations with him telling him to get out of here for a few days because, you know, we’re going to embark on this eight-month journey or so,” Steve Kerr said. “He just can’t stay out of the gym. He wants to be great.”

After participating in a few workouts and one training camp session together, Curry came away impressed by Lendeborg’s thirst for knowledge.

“I don’t think he’s afraid,” Curry said. “He’s open-minded. He’s curious. He’s listening, he’s asking questions. You can tell he’s locked in mentally.”

Lendeborg will need to be ready to roll from the get-go if the Warriors are to improve from last year’s disappointing 37-45 finish. With forwards Moses Moody and Jimmy Butler out for much of the season with knee injuries, the Warriors are missing 32 points and about 10 rebounds per game.

Opportunities to put the ball in the basket should be plentiful for Lendeborg, if his showing at the SoCal runs with Green and Curry are any indication. Lendeborg averaged 14.8 points per game in Vegas and flashed an improved 3-point shot.

But it is his defense that will be tested and needed.

Butler and Moody were the team’s top stoppers a year ago, and without them to close the season, the Warriors dropped to 17th in defensive rating (115.6 points allowed per 100 possessions).

They were also 25th in defensive rebounds per game, a symptom of the carousel-like nature of the frontcourt last season.

With Al Horford not expected to play back-to-backs, Kristaps Porzingis dealing with another mysterious health issue and Green approaching age 37, Golden State desperately needs a player who can do the dirty work on the boards.

Lendeborg’s track record shows a man who can do that.

He twice led the American Conference in rebounding at Alabama-Birmingham before he transferred to Michigan. Standing at 250 pounds, he is larger than many centers.

“Good kid, good size,” Gary Payton II, a man who has made a career of playing larger than his 6-2 height, said succinctly.

Butler also noticed his young teammate’s stature – he exclaimed “He’s (expletive) massive!” at media day. But the veteran also took note of Lendeborg’s willingness to learn.

The six-time All-Star is only participating in “light” on-court activities in his ACL rehab, but his mind has no such restrictions. Lendeborg has taken advantage of Butler’s veteran savvy by peppering the six-time All-Star with all manners of questions.

How to get buckets? That isn’t one of them.