[1] Halvorsen split his first professional season between the rookie–level Arizona Complex League Rockies, High–A Spokane Indians, and Double–A Hartford Yard Goats.
[2] Halvorsen began the 2024 campaign with Double–A Hartford, and earned a promotion to the Triple–A Albuquerque Isotopes in early August.
In 41 total appearances out of the bullpen, he accumulated a 5–2 record and 4.47 ERA with 56 strikeouts across 44+1⁄3 innings pitched.
[3] On August 30, 2024, Halvorsen was selected to the 40-man roster and promoted to the major leagues for the first time.
[4] On September 21, he earned his first career save, tossing a scoreless inning against the Los Angeles Dodgers.