Van Aanholt's replacement, Jason Denayer, had a difficult time defending against Spurs winger Son Heung-min in the 1-0 defeat at White Hart Lane but Moyes insisted the call had to be made in the pre-game warm-up.
"For medical reasons we chose to withdraw him, I won't follow up if you don't mind," Moyes said after the game.
"I'd like to be straight. We advised the referee very late on. I got word of something very late. People can get injured in the warm-up."
Denayer reportedly yelled out to van Aanholt, saying: "You're out injured", to which the Dutchman replied: "Who me? You're joking!"