After spending twelve months with Platense in Primera B Metropolitana, Montero completed a move to Estudiantes on 13 July 2011.[2][3][6] His first goal for them came in a 1–1 draw on 14 October 2012 with Brown, a fixture that also saw him sent off in stoppage time.[2]Deportivo Morón became Montero's eighth team in mid-2014, though the defender would depart in the succeeding January to fellow third tier outfit Deportivo Riestra.[2][7] Eighty-seven matches and three goals came across 2015, 2016 and 2016–17, with the latter concluding with promotion via the play-offs; though they were subsequently relegated back after one season.[8][9]
After one hundred and fifty-one appearances and four goals in five years with Riestra, Montero departed in August 2020 to Almirante Brown; reuniting with Jorge Benítez, who managed Montero at Riestra between July 2016 and September 2018.[10][11]