Career
Guillemaín started out his career playing for his local club, San Juan, before heading to Europe in 2012 to sign for Parisian side Stade Français along with compatriot Lisandro Gomez Lopez. He made his Top 14 debut during the 2012-2013 season, however his appearances for Stade have largely been limited to the Amlin Challenge cup since then He made his senior debut for Los Pumas on 8 November 2014 in a 41-31 defeat to Scotland in Edinburgh.
