[6] The 2018–19 campaign saw the midfielder appear in senior football, firstly as an unused substitute for league fixtures with Tigre and Huracán in November/December 2018.
[3] Miljevic was named as a substitute for a Copa de la Superliga round of sixteen match against San Lorenzo in the succeeding April, subsequently making his professional bow in a 1–0 first leg win at the Estadio Diego Armando Maradona.
[3] On September 13, 2023, it was reported that Miljevic, against the terms of his contract with CF Montréal, played three matches in the indoor amateur Québec Calcetto Soccer League, using the false name Matko Milojevic, where he tallied six goals and two assists.
[7] On September 18, 2023, MLS terminated Miljevic's contract for engaging in conduct detrimental to the league and violating his Standard Player Agreement.
[16][17] In August 2019, Tab Ramos called Miljevic up for September friendlies with the United States U20s, but Argentinos denied his release.