Leeds have already lost Kalvin Phillips and Raphinha this summer and there are now rumours over the future of Harrison at Elland Road.
Newcastle admire the former Manchester City man and are interested in taking him to St. James’ Park in the ongoing transfer window.
The Magpies want to add an attacker and Harrison is one of the players Eddie Howe is very keen on at the moment.
Leeds have remained steadfast in their stance that the winger is not for sale and Marsch stressed that Harrison is part of his plans for the 2022/23 season.
The Leeds boss claimed that Harrison is happy at Leeds, indicating that the player is not pushing for a move.
Marsch said in a press conference: “I think Jack unintentionally brought attention to his situation.
“Always interest in our players, but we feel strongly the guys within our group can help us to be successful and Jack is part of that.
“I know he is happy here.”
Leeds are desperate to keep hold of their other top players after letting Phillips and Raphinha go this summer.
