Whelan knows Cook from their involvement in the sportswear industry.
He told the Manchester Evening News: "The City fans are tremendously loyal, they deserve to see their team be successful.
"I remember playing City in the old third division in front of 40,000 fans at Maine Road.
"City have become a force and they are aiming high and, in Gary Cook, they have a man in charge who can go on to become one of the Premier League's leading administrators.
"I've known Gary for a long time. He's been in the sports business all his life. He's a very good operator and I know just how ambitious he is."