It was a strange night for Ben Simmons in the Nets’ season opener.

He was healthy. Spry. Effective.

And in the end, benched when it mattered most.

Simmons had 10 rebounds, a game-high nine assists and a block. But he logged just 1:53 in the fourth quarter, fellow starting guard Spencer Dinwiddie just 1:21.

The Nets blew a late lead and lost 114-113 to Cleveland, coach Jacque Vaughn citing a need to be more physical and execute better.

“Its not easy to win in the NBA. There’s not a guarantee of winning every night so you got to earn it,” Simmons said.

“We had too many turnovers. I think it just came down to details of the game. Just small plays that we needed that ended up being a huge plays for us. Stops, rebounds and buckets.”

Simmons’ health issues are well-documented, a bad back requiring surgery and limiting him to just 42 games the past two seasons.

Asked if he was on a minutes limit Wednesday, he said he wasn’t.

Asked if he was pulled due to game flow, he replied “You gotta ask coach. I don’t know.”

Backup point guard Dennis Smith Jr. played much of the fourth in place of Simmons and Dinwiddie.

He had 10 points and four rebounds in 15:50 after winning a fitness race to come back from a sprained ankle.

“Overall he was a part of that stretch that really got us back in the game,” Vaughn said. “It was the physicality which he played with that kind of permeated through the group.

“I think he has that ability to do that. So looking forward to him getting to 100 percent, playing minutes for us, being disruptive for us, but I think you felt him when he was out there on the floor.”

Nic Claxton (seven points, seven boards, game-worst minus-12) appeared to be laboring near the end of the game, and had tape on his knee.

“That’s just a part of us trying to play hard and physical. And I do want to build our guys up where eventually, at the end of the season, maybe they have the ability to play extremely hard and 30-plus minutes. That is the goal,” Vaughn said.

“The beginning of the year, just metric-wise, the first 10 games of the year is the highest acceleration and pace that there is throughout the course of the year. So I knew that was going to feel that way once we started the game. I’ll always keep an eye on Nic what his stretches look like. I want him fresh to be able to defend for us and run the floor for us. And so sometimes he’ll have an eight-minute stretch, sometimes those stretches are gonna be four minutes.”

The Nets play in Dallas on Friday, their first meeting vs. Kyrie Irving since the star forced a trade in February.