Blalock spent the 2021 campaign with the Single–A Salem Red Sox, making 23 starts and compiling a 3–6 record and 4.27 ERA with 85 strikeouts over 86+1⁄3 innings pitched.[3] He underwent Tommy John surgery in March 2022, and missed the entirety of the season as a result.[4] Blalock began the 2023 season with Salem, and was promoted to the High–A Greenville Drive after four starts. In seven starts for Greenville, he recorded a 5–1 record and 2.55 ERA with 36 strikeouts across 35+1⁄3 innings pitched.[5]
Milwaukee Brewers
On August 1, 2023, the Red Sox traded Blalock to the Milwaukee Brewers in exchange for Luis Urías.[6] He made 4 starts for the High–A Wisconsin Timber Rattlers down the stretch, posting a 5.27 ERA with 17 strikeouts across 13+2⁄3 innings.[7] On November 13, the Brewers added Blalock to their 40-man roster to protect him from the Rule 5 draft.[8]
He was optioned to the Double–A Biloxi Shuckers to begin the 2024 season.[9] In 7 starts for Biloxi, he recorded a 2.27 ERA with 29 strikeouts across 35+2⁄3 innings pitched. On May 20, 2024, Blalock was promoted to the major leagues for the first time.[10] However, he did not play in a game, and was optioned back to Biloxi on May 24, becoming a phantom ballplayer.[11] On June 19, Blalock was promoted to the major leagues for the second time,[12] and he made his MLB debut the following day.