Maiz started off his career in his homeland with General Díaz.[2][3] He made his professional bow, at the age of seventeen, in a Primera División fixture with Olimpia on 12 February 2018, though was substituted off after thirty-four minutes for Arturo Aranda.[2] Four days later, Maiz started another match against Independiente but was again subbed off early in the first half.[2] In the succeeding November, Maiz scored his first senior goal in a victory away from home to Guaraní.[2] Across the 2018 campaign, Maiz was selected to start nineteen times; appearing for the full duration just once.[2][4] He featured in twenty-one matches in the first part of 2019.[2][5][6]