The midfielder wasn’t involved in the squad at Middlesbrough on Tuesday night, and he has now returned to Goodison Park.
“I spoke to David Moyes at Everton,” Warnock told the club website.
“He wants him to play and I couldn’t guarantee him that. He’s done well, he’s a smashing player, but he needs to play games and I can’t guarantee that.”
He joined Leeds on January 11 and made four appearances.