The text presents the results stemming from a socio-ethnographical investigation (interviews, observations) inside a structure that prepares for the profession of professional football player. This learning requires an extensive commitment and the production of a vocation inside a particularly captivating institution, a professional club. However, this conversion in the sports profession is not independent from social relationships tied up outside of the sports world, in particular in the family and in the networks of sociability. These relations, transformed by the sports ascent, make their contribution to this process of commitment.Le texte présente les résultats issus d'une enquête socio-ethnographique (entretiens, observations) à l'inté...