Three-time NBA All-Star Ben Simmons says he is simply grateful be back on the court after making his long-awaited debut for the Brooklyn Nets in preseason on Monday.

Simmons played 19 minutes in the Nets' 127-108 loss to his former franchise, the Philadelphia 76ers on Monday.

The Australian guard scored six points with five assists and four rebounds in his return, after mental health and injury issues meant he did not play at all last season, even after being traded from the 76ers to the Nets in February.

"I'm grateful just to be able to step on that floor," Simmons said. "Step on an NBA floor again. I had a lot of fun out there.

"That's the one thing, I thought I was going to be nervous, but I wasn't nervous. I was excited."

Simmons' return, which was rusty at times, marked 470 days between games for the 2018 NBA Rookie of the Year.

It is also the first time the Nets have fielded Simmons alongside Kevin Durant and Kyrie Irving, offering excitement for the franchise.

"Ben's playing with a totally different unit than he has in the past, different style," Nets head coach Steve Nash said.

"It's going to be ugly at times, but I thought as the half wore on you definitely started to see glimpses of the potential. The way the ball moved. The way they were hounding the basketball defensively.

"I thought Ben looked pretty good overall and grew into the game through the half."

Simmons admitted that working alongside Durant and Irving would take time but he was excited by the learning process as the Nets build cohesion.

"It was fun messing up because I know how good we can be," Simmons said. "And seeing just different looks and opportunities there with Kevin and Ky and Joe [Harris]. Seeing where they want the ball and just how things are going to work and flow.

"But the only way you learn is to make mistakes so I had a few out there tonight and I can go back and watch film and say I know what I did wrong and how to fix that, so it's all a learning process for me so it's good."