Sane was set to move to Bayern before suffering a knee injury in the Charity Shield at the beginning of the season.
Stoiber confirmed to BILD: "There was a discussion about Sané. The unfortunate injury and the operation stopped it for the first time around. We will see how the contact develops.
"As chairman of the Advisory Board and member of the Supervisory Board, I have great faith in the sporting leadership. If they propose a transfer of this size then that is justified. We know what was required, how the sum was raised. But financial stability is the responsibility of our chief financial officer Jan-Christian Dreesen."