McCormack’s action was taken a day after the unveiling of Dave Hockaday as the new head coach at United, but his decision is not thought to be directly related to the former Forest Green manager’s appointment.
The 27-year-old’s departure from the club has looked inevitable since it was announced that he did not travelled out to northern Italy for United’s two-week training camp in Santa Cristini.
The Scottish international is the subject of considerable interest from Fulham, who are hoping to finalise a deal to take him to Craven Cottage shortly.
Fulham saw a £5m bid for the Scot turned down last month, but have maintained their interest in the forward, who has also been linked with moves to West Ham and Newcastle United this calendar year.
McCormack signed a new four-year deal at United last autumn, but has grown disillusioned with events at Elland Road and held a face-to-face meeting with owner Massimo Cellino expressing his concerns recently, with reports suggesting he had asked to leave.
Fresh reports this morning say he had tabled a transfer request, although the club have not confirmed the development.
Leeds would seek a eight-figure fee around the £10m mark for the services of McCormack, whose current contract runs out in 2017, if they were to cash in on him.
McCormack, who was close to previous manager Brian McDermott, has had plenty to ponder this close season, with the former Cardiff striker forced to weigh up his affection with Leeds with his hopes of playing in the Premier League in the near future, with the forward turning 28 next month.
Speaking at the end of last season, he said: “There’s no point in me sitting here saying that I don’t want to play in the Premier League, because I do. I want to play there as soon as possible, but in my head there’s a lot to take into consideration,”
“I think about the feeling of being at Elland Road on the last day of the season, winning promotion and being captain. That would surpass just playing in the Premier League for any old club, and I don’t say that lightly.
“I’ve had something quite special here, something I’ve never really had before. I’m comfortable and happy and that comes from knowing you’ve got a manager in place who believes in you.”