In 2019, Rojas played for the rookie–level Gulf Coast Phillies and Low–A Williamsport Crosscutters, batting .265/.313/.429 with 2 home runs, 15 RBI, and 14 stolen bases.

[3] He returned to action in 2021 to play for the rookie–level Florida Complex League Phillies, Single–A Clearwater Threshers and High–A Jersey Shore Blue Claws.

[4][5] In 2022, Rojas played for Jersey Shore and the Double–A Reading Fightin Phils, hitting .244/.309/.354 with 7 home runs, 38 RBI, and 62 stolen bases across 130 games.

[13] Rojas was the Phillies' starting center fielder on Opening Day 2024[14] despite poor batting performance in the 2023 postseason and during 2024 spring training.

[17] In 2024 Rojas was one of the fastest players in MLB, with a sprint speed of 30.1 fps, second only to Bobby Witt Jr.. [18] He stole 25 bases and was caught stealing 4 times, in 338 at-bats.