The 28-year-old found himself out of the first-team towards the end of last season as Cardiff secured the Championship title and promotion to the Premier League.
But Mackay believes Whittingham's craft will be vital as Cardiff attempt to make a positive impression in the top flight, and the Bluebirds boss is determined to keep the player.
Mackay said: "We will not be listening to anyone about Peter Whittingham. He is totally part of my squad. He is very much part of my plans for the Premier League now.
"He is a fantastic player and a tremendous young man to have at the club. He's someone who is involved in everything we do and a player who has a very big part to play for us.
"He's signed three contracts for me and he's under contract right now and that is the way things are going to stay.
"He's going to be playing in the Premier League with Cardiff. He is going to get his chance and he thoroughly deserves it after everything he has done for Cardiff City."