Diamondbacks Add Left-Hander Blake Walston to 40-Man Roster
Today was the deadline for teams to add minor league players to the 40-man roster in order to protect them from the Rule 5 Draft. The lone player Arizona added to their roster was left-hander Blake Walston. In order to clear space, they outrighted Chris Rodriguez to Triple-A Reno.
The Rule 5 Draft occurs every December as part of the Winter Meetings, as eligible minor leaguers can be selected by other teams. For a player to be eligible for the major league phase of the draft, they would have to be not on a team's 40-man roster at least four years after originally signing with a team or three if signed at Age 19 or higher. Teams may select a player for $100K and that player would have to spend the entire 2024 season on the active roster or be offered back to his original team for $50K after passing through waivers. Teams occasionally will find a way to get around that, sometimes trading with the original team for the rights to that player.
Walston, 22, was the 26th overall selection in the 2019 Draft due to his projectability, solid mix of secondary pitches, and a max velocity fastball of 97 MPH. His fastball velocity backed up into the 88-92 range in 2023, compared to more 93-97 in Amarillo, which lowers his ceiling more towards a No. 5 starter or a long reliever compared to a potential middle of the rotation arm. Even with concerns about his overall ceiling, the combination of a diverse repertoire of pitches and the D-backs lack of left-handed pitching depth made him someone they could ill afford to lose.
In four years he steadily ascended up the minor league ladder, pitching all of 2023 with Reno. While he didn't have quite the successful year statistically, Walston remained healthy and built up his innings total from 116 in 2022 to 147 in 2023. He'll get his first major league opportunity at some point in the 2024 season, as the team will need 10-12 starting pitchers to get through the year.
With Walston's addition to the roster, the team has two left-handed options to potentially slot in for their rotation during the season. Tommy Henry made significant progress in 2023 before an elbow injury cut his season short. The D-backs could look to add a left-handed starter in free agency or trades as well to shore up their rotation. 20-year-old prospect Yu-Min Lin is also lurking, finishing 2023 with Double-A Amarillo and could be a callup prospect at the end of 2024.
Two other highly ranked prospects, outfielder Kristian Robinson and infielder Deyvison De Los Santos, were not added to the 40-man roster. Both prospects are known for their raw power and rank in the top half of my Top 30 list entering the 2024 season. However the risk those two players will be taken in the major league phase are relatively low. Both slugger prospects are not likely to factor much in the 2024 season, although De Los Santos is closer to a big league call-up with 113 games played at Double-A compared to Robinson's 11.
In the Rule 5 Draft, it's much easier to hide a relief pitcher in the bullpen than it is to hide a hitter on the bench, so it's less likely teams will take a flyer on an unpolished bat. In the event both players remain unselected in the major league phase, it's likely they'll be protected from the minor league phase.
