"If he gets an offer from a big team then we should give him the chance to go, but the teams who've asked for McCormack are from the Championship," the Italian told reporters.
"Why should I sell McCormack? We are not desperate to sell him so why should we? If I needed the money, I would tell you frankly – I need the money, I have to sell, I'm not ashamed.
"McCormack is a matter of principle, not money. He's a beautiful player and he's staying at Leeds."
The 27-year-old, who has three years remaining on his current deal, scored 29 goals last season.