[3] He made his professional debut that year with the Gulf Coast Marlins where he went 4–3 with a 2.18 ERA in 11 games (seven starts).

[9] Paddack was invited to spring training by the Padres in 2019 and dominated, pitching to a 3-1 record and a 1.76 ERA in 5 games, earning him a spot on the team's opening day rotation.

[10] On March 31, 2019, he made his major league debut with a start versus the San Francisco Giants.

[12] During his 2019 season, he earned the nickname "Paddack Attack" for his first-pitch strike-heavy approach and relentless assault on opposing hitters with his fastball and changeup combination.

On April 7, 2022, the Padres traded Paddack, Emilio Pagán, and a player to be named later to the Minnesota Twins in exchange for Taylor Rogers, Brent Rooker, and cash considerations.

[16] On January 13, 2023, Paddack agreed to a one-year, $2.4 million contract with the Twins, avoiding salary arbitration.

[18] On September 24, Paddack was activated from the injured list to make his return from Tommy John surgery.