Diamondbacks add LHP Blake Walston to 40-man roster for Rule 5 Draft protection

The Arizona Diamondbacks added left-handed pitching prospect Blake Walston to their 40-man roster and outrighted Chris Rodriguez to Triple-A Reno, the club announced.

Tuesday was Major League Baseball’s deadline to set 40-man rosters and protect players from the Rule 5 Draft on Dec. 6 at the Winter Meetings.

Players who sign with clubs at 18 years old or younger need to be on the 40-man roster within five seasons to avoid being eligible for the Rule 5 Draft. Those who sign at 19 years or older need to be on the 40-man roster within four years. Teams don’t have to make a Rule 5 selection (15 in 2022), as picks land directly on their drafting club’s 26-man roster.

Walston is 22 years old after originally signing before his 18th birthday.

The 6-foot-5 southpaw was picked No. 26 overall by Arizona in the 2019 amateur draft, 10 spots after National League Rookie of the Year Corbin Carroll. The D-backs used a compensatory pick — awarded after 2018 first-rounder Matt McLain did not sign — on the high school arm from North Carolina.

Walston spent the 2023 season in hitter-friendly Triple-A Reno and started 30 games with a 4.52 ERA, 1.57 WHIP, 5.6 walks per nine innings and 6.3 strikeouts per nine innings. Walston finished the year with three straight quality starts, although he walked nine batters and struck out eight over those 18.1 innings. He started one game in the Arizona Fall League for the Salt River Rafters and tossed three scoreless innings.

Don’t forget about the baseball at Salt River Fields 👀

Blake Walston was dominant in his first Arizona Fall League showing 🔥

His Final Line:
– 3️⃣ IP
– 0️⃣ R
– 4️⃣ SO pic.twitter.com/CKBWEVdyh8

— Reno Aces (@Aces) October 6, 2023

MLB Pipeline had Walston ranked No. 4 on Arizona’s prospects list after the 2022 season, but he fell to No. 27 this past year. FanGraphs had him No. 16 in Arizona’s system on its latest rankings.

Walston joins a group of young starting pitchers on the 40-man roster that includes Brandon Pfaadt, Tommy Henry, Ryne Nelson, Slade Cecconi, Bryce Jarvis (moved to bullpen in 2023) and Drey Jameson (Tommy John surgery).

Arizona claimed Rodriguez off waivers from the Los Angeles Angels on Oct. 30. The 25-year-old right-hander had a 3.64 ERA in 29.2 innings back in 2021, but injuries have kept him off the mound in the major leagues since.

The Diamondbacks left outfielder Kristian Robinson (Arizona’s No. 11 prospect on MLB Pipeline) unprotected after he returned to minor league play this season for the first time since 2019. Arizona designated Robinson for assignment in August to clear a roster spot, but he went unclaimed and remains in the organization.

D-backs No. 5 prospect Deyvison De Los Santos is also Rule 5 eligible, although he has not played beyond Double-A.

Last year, the Diamondbacks did not protect outfield prospect Dominic Canzone, but he did not get picked in the Rule 5 Draft. He remained with Arizona and was a trade piece in the package for closer Paul Sewald at the deadline.

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