The 22-year-old has been heavily linked with a switch to AC Milan, who have been reported to have opened negotiations with the player.
"I saw that speculation yesterday but I've not heard anything," Platt said in a press conference. "As far as we are concerned I think he is still a Manchester City player. I don't think anything is going to happen."
Meanwhile, AC Milan have also attempted to quash their link with the Italy international, who is reported to have been given a £28m price tag.