The England international has lost his central defensive position to Serbian teenager Matija Nastasic in recent times but could not even make the bench with Kolo Toure preferred.
But Platt has eased any fears the former Everton man could be on his way out at the Etihad Stadium.
"Joleon is fine. He will be available for selection like he was available for selection at the weekend,â€ť he said ahead of Wednesday nightâ€™s meeting with Wigan Athletic.
"He has been available for selection for a few games, but we can only put 11 on the pitch."