The Seattle Mariners have acquired RHP Diego Castillo from the Tampa Bay Rays in exchange for RHP JT Chargois and 3B Austin Shenton.
Man, do the Rays love to sell when they are up. Castillo is their best relief pitcher and the closest thing that they have to a closer. He also has not hit arbitration yet. He starts the process next year and will have three extra years of team control for Seattle. If you are dealing a player as good as Castillo with years left, you better get a haul. What the Rays got is about standard for a rental. That is not to say that the Rays got nothing in return. Chargois signed a minor league contract this offseason with Seattle and has become a very solid relief arm for them. He has over six inches of extension on his pitches, making his velocity seem faster than it really is. At an average of just under 96 mph, he throws hard at surface value. Batters have just a 5.1 BB% this year against him and Chargois has a very solid 3.56 xERA. He can turn into a late-inning arm in Tampa Bay. MLB Pipeline ranked Shenton as the 17th best prospect in the Seattle system prior to the deal. He was a 5th round pick in 2019 and his lit up the minor leagues since arriving. Knowing the Rays, this deal has a ton of potential.
Chargois, 30, has a 3.00 ERA with 29 strikeouts and a 0.967 WHIP in 30 innings for the Mariners this year. In his MLB career for the Mariners, Los Angeles Dodgers, and Minnesota Twins, Chargois has a 4.13 ERA with 114 strikeouts and a 1.247 WHIP in 106.2 innings.
Shenton, 23, has hit 11 home runs with a .414 OBP and a .980 OPS in 321 Plate Appearances for Single-A Everett and AA Arkansas this season. In his minor league career Shenton has hit 19 homers with a .399 OBP and a .940 OPS in 547 Plate Appearances.
The Rays could easily develop Chargois and Shenton into great players but that should not hold the Mariners back. Castillo is as elite as it comes in the pen and is a perfect make-right for the clubhouse that was irate after closer Kendall Graveman was dealt. He has a 2.34 xERA with a .185 xBA, a .302 xSLG, and a .237 xwOBA. Those are all amazing numbers. He has also decreased his walk rate this year. His slider’s whiff rate has gone down in 2021, but to a very good 40 percent. This is a great add for GM Jerry DiPoto.
Castillo, 27, has a 2.72 ERA with 49 strikeouts, a 0.991 WHIP, and a 3.15 FIP in 36.1 innings for the Rays this year. In his MLB career, all for Tampa Bay, Castillo has a 2.99 ERA with 218 strikeouts, a 1.080 WHIP, and a 3.58 FIP in 183.1 innings.