Australian star Ben Simmons has had a rough night out in his return to the NBA, scoring just four points and fouling out of the Brooklyn Nets' season-opening loss to New Orleans.

After earning some plaudits in the preseason for his defence on two-time MVP Giannis Antetokounmpo, Simmons came up against one of the few players in the league who could be considered as physically imposing, spending most of his time on court defending Zion Williamson.

Simmons fouled out early in the fourth quarter with four points, five assists and five rebounds, and the team was outscored by 26 points in his 23 minutes on court as the Nets were well beaten 130-108 by the Pelicans.

Simmons missed all of last season with Philadelphia due to back and mental health issues, ensuring all eyes were on the three-time All Star's first regular-season minutes since an unceremonious exit from the 76ers.

And the 26-year-old did nothing to turn around his critics against the impressive Pelicans, who were buoyed by the performance of their own fit-again powerhouse forward, Williamson (25 points, nine rebounds, three assists, four steals).