[2][4] Rojas had youth periods with Club Arzeno and Atletico Pueyrredón, prior to joining San Lorenzo in 2005.

[1][5] His senior career got underway with Argentine Primera División side San Lorenzo in 2016.

[2][6] He made his first-team debut on 17 November 2016 during a Copa Argentina defeat to Gimnasia y Esgrima, which was followed by his first Primera División appearance on 25 March 2017 against Quilmes.

[2] After debuting in a win over Danubio, he appeared twenty-three times in twelve months there.

[2] On April 9, 2021, Rojas scored a spectacular overhead kick from the edge of the 18 yard box in the 75th minute against Platense to put San Lorenzo 3–2 up.