Steven Ribery has been training with Bayern's youth team since August and has done enough to persuade coaches at the Allianz Arena that he serves a full contract.
The teenager, who primarily plays as an attacking midfielder or support striker, will now fight for a place in Bayern's Under-19 side after putting pen to paper on a trainee deal with the treble winners.
His older brother Frank has revealed that he took Steven under his wing at Bayern after watching his sibling become disillusioned with the game at Lens.
He told L'Equipe: "It was not my character. He just dropped football, mentally. I have taken him with me for fifteen days.
"He suffered as he had never experienced in his life, he trains twice daily. He vomited, lost ten, twelve pounds.
"I want him to succeed. At what level, I do not know. But he has quality."
Franck has become a star for club and country during seven seasons at Bayern, playing more than 250 times for the Bavarian giants.