Celtic manager Neil Lennon has told Team GB coach Stuart Pearce that Scotland winger James Forrest will not be available for the Olympics.
Forrest, who remained on Pearce's shortened list of contenders, missed the last two months of the season.
"James Forrest will not be going because he's been injured. Stuart's aware of that," Lennon told STV.
Bannan is enjoying the sunshine with Scotland in Florida, where they face USA
"He was in his thoughts, but the fact that he's been out for so long probably rules him out."
In addition to 20-year-old Forrest, English striker Gary Hooper had often talked about the possibility of being chosen as an over-age player for the under-23 tournament.
But Lennon said he did not expect to lose players for the tournament.
"Certainly not the British players - we've spoken with Stuart on that," added the Celtic manager, who is keen to have his whole squad available for Champions League qualifiers.
Forrest had already indicated that, if it was a choice between being involved in his club's European campaign or playing in the Olympics, he would not play at the Games.
That news comes as Barry Bannan was quoted in newspapers as saying he would have to speak to Scotland coach Craig Levein about the possiblity of playing in the London event.
The 22-year-old Aston Villa midfielder, in Florida ahead of Saturday's friendly against the United States, said he had been keen to play until he realised the level of opposition from fans and the Scottish Football Association to Scottish players taking part.
South Korea have said they plan to call up Celtic midfielder Ki Sung-yueng, but the 23-year-old's birthday falls weeks outside the deadline that would make his attendance compulsory under Fifa rules.
Lennon added: "As regards the rest of the players, we'll speak to the other federations regarding that and hopefully there will be some sort of resolution where they are playing with Celtic when the time comes."
Wolves striker Steven Fletcher, who has been told by Levein he will not play for Scotland again while he is in charge after a disagreement between the two, remains in the running to make Pearce's GB squad.