Henn started his career with Hindu Club in Argentina. In 2005, he was signed by the top French club Stade Francais who compete in the Top 14. After one season, in 2006, he joined US Montauban who play in the Top 14, the first level of domestic competition in France. He was signed by CA Brive. After 5 seasons, he left Brive and he signed for Limgoes for the 2013-14 season, competing in Federale 1, the third level of domestic competition in France. On 10 July 2014, Henn was signed to the English club London Welsh who compete in the Aviva Premiership from the 2014-15 season.[1]