In 2018, he split the year between the Low-A Hillsboro Hops and High-A Kane County Cougars, hitting a cumulative .292/.378/.468 with 9 home runs, 40 RBI, and 17 stolen bases across 70 total games.

[3] For the 2019 season, he began the year playing for the High-A Visalia Rawhide, posting a .268/.388/.396 with 3 home runs, 12 RBI, and 28 stolen bases in 43 contests.

[5] Caballero split the 2021 season between the rookie-level Arizona Complex League Mariners, High-A Everett AquaSox, and Double-A Arkansas Travelers.

[7] He made his MLB debut that night as a defensive substitution, replacing J. P. Crawford at shortstop in the ninth inning against the Colorado Rockies.

[10] On May 21, 2023, he hit his first major league home run off Nick Anderson of the Atlanta Braves, in the process becoming only the second Mariner after Mike Cameron to record a homer and three stolen bases in the same game.