MK Dons are resigned to losing Brendan Galloway, with a number of Premier League clubs reportedly interested.
The Zimbabwe-born playmaker, 18, formally expressed his desire to leave the club through his advisors.
Galloway made 13 appearances last season, scoring in the Dons' 4-1 FA Cup first-round tie against Halifax.
"We are devastated that Brendan wishes to leave, as we feel our first team is the best place for him at the moment," chairman Pete Winkelman said.
"There has been interest from several Premier League sides in Brendan and we fully appreciate the lure of the top-flight is enormous.
"We accept that Brendan may have played his last game for the club, but we will remain in discussions with interested parties to ensure MK Dons receives the best possible deal for one of the country's brightest young talents."
The former MK Dons trainee made his first start for the club in November 2011 in a 6-0 FA Cup win against Nantwich Town.
BBC Three Counties Radio understands that Everton are one of the Premier League clubs interested in Galloway, who did not travel with MK Dons to Ireland for their pre-season training.
"I gave Brendan his debut at the age of 15," manager Karl Robinson told the club website. "I've seen him grow into a very talented footballer."