McCormack, who has handed in a transfer request, has been the subject of two bids from Fulham, with the Cottagers in pole position to sign the Scotland international.
Speculation that McCormack's days at the club were numbered gathered pace on Monday when he failed to head out to the club's summer training camp in Italy with the rest of the first-team squad.
But a Leeds statement read: "Leeds United owner Massimo Cellino and the club would like to respond to recent media speculation regarding Ross McCormack.
"We would like to reiterate our desire to keep Ross McCormack at Leeds United. This desire includes keeping all of our best players as we look to build a stronger and successful squad for the 2014/15 Championship season.
"Leeds United may not be the richest club in the Championship, but we do not need to sell our best players in order to run the club successfully."
West Ham failed in their bid to sign McCormack in January, while Newcastle, former club Cardiff, Norwich and Derby have also been linked with the 27-year-old.
When Hockaday was unveiled by Cellino earlier this month, the Italian insisted the Scot would only be sold for the right price to a Barclays Premier League club.
Cellino said he had blocked McCormack's proposed move to Fulham's London rivals West Ham in January. He also claimed he rejected an approach from a North-East club in recent weeks.