Gilbert Arenas went on a rant filled with xenophobic tropes following Team USA's win over South Sudan ... and he's now facing backlash for the remarks, including from Joel Embiid, who's calling the comments "disappointing."
The former NBA star unleashed the offensive tirade on Saturday ... just after LeBron James and Co. squeaked by South Sudan in an Olympics tuneup, 101-100.
James' squad was supposed to win big at O2 Arena in London -- they were, after all, 43-point favorites -- but instead, they needed a last-second layup from the Lakers superstar to get them by.