Born in Bourg-en-Bresse, Ain, Yoann began his career with amateur side ASOA Valence in Drôme.
[2] Just five days later, he started again in a UEFA Cup tie against Belgian side Club Brugge.
He also started in Saint-Étienne's upset victory on 3 January 2009 over Bordeaux in the Coupe de France.
His positive performances earned him his first professional contract, signing with ASSE for a period of three years.
[3] After the end of the 2018–19 season Andreu announced his retirement as a player due to knee problems.