Hollowell did not play in a game in 2020 due to the cancellation of the minor league season because of the COVID-19 pandemic.
[3] Hollowell spent the 2021 season split between the rookie-level Arizona Complex League Rockies and Single-A Fresno Grizzlies.
In 24 combined appearances, he posted a 3-0 record and 2.25 ERA with 33 strikeouts and 5 saves in 24.0 innings pitched.
[4] Hollowell began the 2022 season with the Double-A Hartford Yard Goats, pitching to a 4-2 record and 3.14 ERA with 64 strikeouts and 16 saves in 42 appearances.
[5] He made 6 appearances for Colorado in his rookie campaign, posting an 0-2 record and 7.71 ERA with 8 strikeouts in 7.0 innings pitched.