Ben Simmons has been greeted with a chorus of boos and a river of vitriol on his return to Philadelphia, after agitating for a trade away from the 76ers this season.

Simmons still has not played a game for the Brooklyn Nets but was on court before the game in Philly, warming up with the team, firing up his former fans.

He walked onto the court with fellow Aussie Patty Mills, but even Mills's almost 100 per cent approval rating from basketball fans could not prevent the boos from raining down.

Simmons dapped up teammate Kevin Durant and even cracked a few smiles as he helped Mills and other teammates warm up while the crowd continued jeering.

The boos and hisses turned to sarcastic cheers when Simmons dunked a ball, bringing back memories of perhaps his lowest on-court moment in Philly, when he passed up an open dunk with his team down two late in the fourth quarter of a series-deciding game seven against Atlanta in the 2021 play-offs.

The Wells Fargo Center in Philadelphia increased security for the game and the court was cordoned off from the stands by guards and ushers in a manner usually reserved for NBA Finals celebrations, when hundreds of people stream onto the hardwood.

NBA on TNT reporter Stephanie Ready said the 76ers told her tickets for this game were the "most in-demand" for any game in the past decade, including play-offs.

With even the worst ticket in the arena going at $US200 ($272) and closer seats priced around $US4,000 ($5,442), former 76er and basketball hall of famer Charles Barkley said many of the fans in the arena were not there for the quality basketball.

"Those fans are there for hatred," he said on TNT.

"They don't care about this game at all. They're there for one reason.

"They're not paying $4,000 for no damn regular season game."

T-shirts calling Simmons a dickhead were being sold outside the arena, while inside, some fans wore modified jerseys of the former number one draft pick, calling him soft and a baby.

Once the game started, chants of "f*** Ben Simmons" rung out, but his teammates did their best to hit back, dropping 40 points in the first quarter thanks to 11 points each from Kevin Durant and Kyrie Irving.

Joel Embiid tried to keep the Sixers afloat, scoring 16 of their 23 first-quarter points, drawing three early fouls from Nets big man Andre Drummond, getting into an on-court argument with Durant and finishing with a team-leading 27 points and 12 rebounds.

Meanwhile, James Harden, who was the centrepiece of the trade for Simmons, struggled from the field in the game, knocking down just three of 17 shots from the field for 11 points in 28 minutes against his former Nets teammates.

Sharp-shooter Seth Curry, who was traded with Simmons to Brooklyn, scored 24 points, almost matching superstar Durant, who top-scored for the game with 25.

Irving finished 22 and Mills had 10 as the Nets won the game 129-100.