Miller attended De Smet Jesuit High School in Creve Coeur, Missouri.
[7] The Philadelphia Phillies selected Miller in the fourth round of the 2019 Major League Baseball draft.
[11] Miller did not play in a game in 2020 due to the cancellation of the minor league season because of the COVID-19 pandemic.
[21][22] On January 9, 2023, the Phillies traded Miller to the San Francisco Giants in exchange for Yunior Marte.
[23] In 54 appearances split between the Double–A Richmond Flying Squirrels and Triple–A Sacramento River Cats, he accumulated a 2.45 ERA with 88 strikeouts and 15 saves across 62+1⁄3 innings pitched.