Ben Simmons with boos and trash talk as he took the court

Simmons finally got what he wanted last month ... after the Sixers traded BS, Seth Curry and Andre Drummond to the Brooklyn Nets in exchange for James Harden.

Simmons returned to Wells Fargo Center -- this time as a visitor -- in black and white gear for Thursday's matchup against the Sixers ... and despite being out with an injury, the fans let him hear it during pre-game shootaround.