Walston attended New Hanover High School in Wilmington, North Carolina.
[3] Walston was also named the 2019 North Carolina High School Player of the Year by Perfect Game.
[4] He committed to play college baseball at North Carolina State University.
[5] The Arizona Diamondbacks chose Walston in the first round, with the 26th overall pick, in the 2019 Major League Baseball draft.
[14] On November 14, 2023, the Diamondbacks added Walston to their 40-man roster to protect him from the Rule 5 draft.