[6] He lived on rue de la Faisanderie, in the 16th arrondissement, barely 300 meters from the parish church of Saint Honoré d'Eylau, where the Étoile club was based.
[7] Sellier was a member of the Étoile team that won the FGSPF Football Championship in 1907, and this victory allowed the club to compete in the inaugural edition of the Trophée de France in 1907, an inter-federation national competition organized by the CFI, which had just been founded by Simon.
[5][8] In the day after Wanstead, on 29 March, he started for the CFI's Paris selection against the prestigious English club Bishop Auckland, winner of 3 FA amateur Cups, helping his side to an impressive 1–0 win.
[5] Shortly after being released from his military obligations, Sellier was mobilized by France at the outbreak of the First World War in August 1914, being assigned to the 40th Field Artillery Regiment.
[5][11] There, a fall from a horse on 1 September 1917, while on "commanded service", caused a skull fracture that left him with after-effects, such as deafness in one ear, dizziness, and headaches.