Revisiting Mariners’ Luis Castillo trade as it enters a new chapter

The book is far from closed on the trade the Seattle Mariners made to acquire Luis Castillo from the Cincinnati Reds during the 2022 season, but a new chapter began this week.

Seattle Mariners will have one big advantage at the trade deadline

Shortstop Edwin Arroyo was called up from Triple-A and made his major league debut for the Reds on Monday, making him the third and perhaps last of the four players sent to Cincinnati for Castillo to reach the major leagues.

Arroyo was one of the Mariners’ top prospects at the time of the trade, ranked No. 3 in the organization by MLB Pipeline. He went to the Reds alongside shortstop and No. 1 M’s prospect Noelvi Marte, right-hander and No. 5 prospect Levi Stoudt, and right-hander Andrew Moore.

We won’t know who won this trade or if was a win-win for both sides for quite a while, but with Arroyo reaching the majors, it’s a good time to take a look back at what each team has gotten from the deal thus far.

Mariners

Castillo immediately became the ace of the Mariners’ staff and was an instrumental part of their runs to the playoffs in 2022 and 2025, the former of which ended the franchise’s 21-year postseason drought.

In his 11 starts for the M’s down the stretch in 2022, Castillo posted a 3.17 ERA over 65 1/3 innings. He also made two playoff starts, including a brilliant outing in Game 1 of Seattle’s wild-card series against Toronto, tossing 7 1/3 scoreless innings to earn his first career postseason win and the franchise’s first since 2001.

And before the playoffs even began, the Mariners locked down Castillo to a five-year contract extension through the 2027 season.

Castillo, now in his fifth season in Seattle, has lived up to his nickname “The Rock” as a solidifying member of the Mariners’ rotation. He was the opening day starter in 2023 and ’24, he earned an All-Star nod and finished fifth in American League Cy Young voting in 2023, and he’s made at least 30 starts in each of his three full seasons with the club.

In 118 appearances (116 starts) since joining the Mariners, he has a 42-36 record, 3.63 ERA and 1.17 WHIP over 673 2/3 innings. He’s seventh in team history in career ERA and 10th in career strikeouts (689).

Castillo had accumulated 8.4 bWAR as a Mariner coming into this season, but that number has dropped to 7.5 after his rough start to 2026.

Reds

The trade has been somewhat of a rollercoaster for the Reds.

Early on, it looked as if Marte was destined for a stellar big league career. However, it’s been a tumultuous past few years since an impressive 34-game showing in 2023 when he hit .316 with an .822 OPS and three homers.

Marte received an 80-game suspension after testing positive for a performance-enhancing substance before the 2024 campaign. When he returned, he batted just .210 with a .549 OPS and four homers in 66 games.

An oblique injury then limited Marte just 90 games last year, but he was effective when healthy, producing a .263 average, .748 OPS and 14 homers.

The 24-year-old Marte, who is now a right fielder, started this season on the opening day roster for the first time in his career. After batting .138 with no extra-base hits in 11 games, he was sent down to Triple-A on April 13. He was just recalled on Wednesday.

Arroyo’s path has been a little bit of the opposite.

He had some initial struggles after the trade and a modest 2023 in High-A. Then in 2024, he suffered a season-ending torn labrum in his left shoulder during spring training.

Arroyo started to fall in prospect rankings after 2024, but bounced back with a solid 2025 in Double-A.

Before being called up Monday, the 22 year old was tearing up Triple-A pitching, batting .323 with a .945 OPS and 11 homers in 53 games.

Stoudt, 28, got a brief taste of the majors in 2023, posting a 9.58 ERA with 11 runs allowed in 10 1/3 innings over four appearances (two starts). He hasn’t pitched in the majors since.

Stoudt returned to the Mariners’ organization in February 2024 after he was designated for assignment by the Reds, but he was DFA’d by the M’s later that season. He’s now pitching for the Philadelphia Phillies’ Triple-A affiliate.

Moore, 26, has yet to reach the majors. The Reds traded him to the San Diego Padres in May 2025 alongside cash to acquire Connor Joe, who coincidentally signed with Seattle this past offseason. Moore is currently pitching in Double-A.

So far, the Reds have received minus-0.3 bWAR from the trade. But there’s still a lot of time for Arroyo and Marte to try to make up the nearly eight-win gap between what each team has received from the deal thus far.

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