The Cardinals have selected Mills with the 120th overall pick in the 2021 first-year player draft.

After a dominant showing in the Northwoods League last summer, Mills wasn't fully able to maintain that success during his third season at Washington State in 2021, but he still submitted a strong 83:22 K:BB across 80.1 innings. Though the right-handed Mills offers good size (6-foot-4, 225 pounds) and commands his three-pitch arsenal well, he lacks a truly dominant pitch that can routinely generate swings and misses.