The Real Madrid star feels fans' criticism of his teammate is "unfair", calling for all players to be treated equally by the Bernabeu faithful.
The Frenchman failed to convert a number of chances after his side had ceded an early goal to the visiting side at the Bernabeu and was once again singled out for criticism by the home supporters.
The 25-year-old was replaced by Alvaro Morata with 10 minutes remaining and Di Maria was upset with the jeers that greeted the former Lyon man's departure.
"I found the whistles to Karim ugly," the Argentina international told reporters. "Morata missed another chance and nobody whistled him. You must be fair with everybody."
The former Lyon man, who was also whistled by the Madrid public in his side's previous home game with Athletic, had scored twice in the Champions League in midweek.
Real Madrid's next home game is a derby clash with Atletico on Sept. 28.