Seattle Mariners drop nuke by acquiring Luis Castillo from Cincinnati Reds

The first major pitching trade has happened, and it should not be a surprise that the Seattle Mariners were involved.

As first reported by Jeff Passan from ESPN, the Mariners have acquired Luis Castillo. In exchange, Ken Rosenthal of The Athletic reports that they are sending four prospects – Noelvi Marte, Levi Stoudt, Edwin Arroyo, and Andrew Moore – to the Cincinnati Reds.

Seattle Mariners take definitive step to ending playoff drought

Castillo was considered one of the two top pitchers available at the trade deadline. The Reds’ ace has posted a 2.86 ERA and a 1.071 WHiP in his 85 innings, striking out 90 batters with 28 walks. He now gives the Mariners another top of the rotation arm as they look to end their 21 year playoff drought, checking off one of their biggest boxes when it comes to upgrading the roster.

The Mariners also paid a steep price. Three of their top five prospects are heading back to Cincinnati as the Reds are looking to completely reshape their roster in the next year or two. However, that was a price they needed to pay as Rosenthal also reported that the Rangers were close to landing Castillo before that trade came through.

Marte is going to generate the most attention of that quartet. He is considered the 18th best prospect in the game per MLB.com, his tremendous raw power on par with Julio Rodriguez. His solid approach leads to an ability to hit the ball hard to all fields and he is also capable of working the count and drawing walks. There are questions about his consistency as he can lose his approach at the plate at times, and whether or not he will stick at short, but he has the type of power that can make an impact as he develops.

Arroyo is another shortstop, albeit a completely different player than Marte. He has the athleticism and defense to stick at short, although his offense is more about potential at this point. A switch hitter with a solid ability to make contact, it is believed that he will grow into some extra base pop as he matures, something that is beginning to manifest as he has 13 homers in 410 plate appearances in Modesto. However, he has also struck out 90 times, something that should not be a surprise given that he is 18 playing in full season ball.

Stoudt had Tommy John surgery shortly after signing, something that was known would be needed before the draft. He has recovered about as well as anyone could have hoped as he came out of his rehab with an improved slider and impressive command. His slider and changeup are both potential plus pitches, with his command of the slider almost robotic. His fastball could be a plus offering as well, especially when he throws it up in the zone. Stoudt rounds his arsenal out with a solid curve, giving him the potential to be a middle of the rotation arm if he continues to develop.

Moore may not be one of the Mariners’ top 30 prospects, but he is an intriguing minor league reliever. A 14th round selection in the 2021 MLB Draft, he has a fastball that reaches the up 90s with a high spin rate and impressive breaking stuff. He had dominated at Modesto, posting a 1.95 ERA with 58 strikeouts in 32.1 innings. If he can harness his arsenal, he could be a weapon in the later innings.

It is easy to categorize this as an overpayment for the Mariners. They certainly gave up a large chunk of the farm in order to bring Castillo on board. It is also worth noting that he is under team control through 2023 and that the Mariners have focused on this year as the one where they return to the postseason. Prospects are not a given and at some point, the Mariners needed to make this type of a move.

The Seattle Mariners have made the first major pitching move of the deadline in acquiring Luis Castillo. Chances are, they are not done improving the roster.