Career
Born in Posadas, Monllor started his career at Nueva Chicago in the Argentine second tier, adding up nearly 100 league appearances in the 10 seasons he spent there. On 28 June 2014, Monllor moved abroad for the first time in his career, joining newly promoted Boavista in Portugal. He debuted on 17 August 2014, in a match against Braga, but only appeared sporadically throughout his first year, acting mainly as back-up to Mika.