[2] After his senior year in 2017, the Baltimore Orioles selected him in the 38th round of the 2017 Major League Baseball draft,[3] but he did not sign a professional contract.

[12] Miller made his professional debut as the starting pitcher on Opening Day in 2021 for the Great Lakes Loons of the High-A Central, striking out five batters over three innings while allowing only two singles and a walk.

[13] On July 24, Miller pitched five innings of a combined no-hitter against the Lake County Captains alongside Clayton Beeter, Jake Cantleberry, and Cameron Gibbens.

[17][18] He returned to Tulsa to begin the 2022 season, where he made 19 starts and went 6–6 with a 4.45 ERA and 117 strikeouts over 91 innings[15] and was selected to represent the Dodgers at the 2022 All-Star Futures Game.

[15] Miller reported to spring training with a sore shoulder in 2023, leading to him missing the Cactus League schedule and getting a late start on the season, not joining Oklahoma City until the end of April.

[25] Miller started the second game of the 2023 National League Division Series but struggled with his command, allowing three runs on four hits and two walks in only 1+2⁄3 innings.

[30] However, his following outings were not as promising and after he allowed a career worst nine runs in four innings against the Philadelphia Phillies on July 9, he was optioned to the minor leagues.