Rumors of Boston Red Sox trade for Luis Castillo intensify, ‘win-win’ return for Seattle Mariners revealed

Rumblings of the Boston Red Sox completing a trade for Seattle Mariners pitcher Luis Castillo are intensifying. And a top MLB insider recently proposed a trade scenario that would make a deal a “win-win” for both teams.

Heading into the offseason, the Red Sox front office had an edict from the very top to improve the roster by any means necessary. It is an understandable reaction to a trio of .500 or worse seasons for the team. That is why they made a strong push for top free agent Juan Soto.

Related: Boston Red Sox rumors reveal 2 SP targets following Garrett Crochet trade

However, despite their best efforts, Boston finished well behind the New York Mets in the Soto sweepstakes. While they struck out trying to sign the best player in free agency, they quickly bounced back by completing a blockbuster trade for the best player available on the trade market. All-Star pitcher Garrett Crochet.

The Red Sox have been linked to several other players recently. But the most notable MLB rumor is of them attempting a second trade for a big-time pitcher. This time for Seattle Mariners veteran Luis Castillo. MLB.com insider Mark Feinsand added to the speculation on Monday when he wrote “The Red Sox would seem like a strong match with the Mariners.”

However, what could the return before Seattle in a trade for one of the better pitchers? That was also revealed Tuesday.

  • Luis Castillo stats (2024): 11-12 record, 3.64 ERA, 1.169 WHIP, 175 strikeouts, 175.1 innings pitched

Boston Red Sox would have to fork over a pair of top infield prospects in a Luis Castillo trade?

Rumors of Boston Red Sox trade for Luis Castillo intensify, 'win-win' return for Seattle Mariners revealed
Credit: D. Ross Cameron-Imagn Images

“[The Mariners] should keep all of their young starters and be willing to move Castillo, which would also lessen their future financial exposure and potentially help them acquire more bats,” The Athletic’s Jim Bowden wrote on Tuesday. If the Red Sox don’t land free-agent ace Corbin Burnes, which they are trying to do, they could pivot and sign Bregman to play third base, which would necessitate a move of Rafael Devers to first.

“And allow them to trade [Tristan] Casas and a corner infielder such as prospect Blaze Jordan for Castillo to further improve their rotation,” the former MLB GM wrote. “Casas, 24, profiles as a future 25-30 home run power bat. He won’t be eligible for arbitration until 2026. Jordan, who will turn 22 this week, was a third-round pick in 2020. He batted .261/.305/.388 with seven homers and 22 doubles last season at Double-A. A win-win for both organizations.”

Luis Castillo contract: Five years, $108 million

While both teams would like to hold on to players like Castillo and Casas for different reasons, adding the other would help address big needs for both franchises this offseason. Pitching for the Boston Red Sox and hitting for the Seattle Mariners.

Related: Ichiro working to help recruit top free agent to Seattle Mariners

Related Posts

🚨 MLB INSIDE RESET: The White Sox’s newly assembled coaching staff is raising quiet but serious questions across the league, as subtle hires, shifted responsibilities, and a clear change in philosophy hint at a deeper organizational reset. What looks like routine restructuring on the surface may actually signal a long term plan that hasn’t been fully explained yet — and insiders believe the real impact will only become clear once the season pressure hits.

The Chicago White Sox have finalized their coaching staff for the 2026 season following sweeping changes made at the end of September.

🚨 MLB INSIDE TRADE RUMBLINGS: The Braves are suddenly being linked to a bold trade for a $6 million NL rival left hander, a move insiders say could quietly solve multiple problems at once and even position him as a long term heir to Chris Sale. What looks like a low risk deal on paper may actually hide a far bigger plan, with Atlanta reportedly intrigued by a dynamic arsenal that hasn’t fully been unlocked yet — and the timing of this rumor is raising serious eyebrows across the league.

The Braves could go after a young star.

🚨 MLB INSIDE STORM BREWING: As hopes of an Alex Bregman return quietly fade, a new projection suggests the Red Sox may be preparing a jaw dropping $186 million swing for Bo Bichette, a move insiders believe could redefine Boston’s future in one bold stroke. What once seemed unrealistic is now gaining traction behind the scenes, and if this prediction turns real, the ripple effect could shock the AL East and completely change how this offseason is remembered.

A former MLB executive now believes that the Boston Red Sox will land coveted free agent infielder Bo Bichette from Toronto.

🚨 MLB INSIDE WHISPERS: Something big is quietly brewing behind closed doors in New York, as new projections hint the Yankees may be lining up an elite shortstop signing that goes far beyond a normal free-agency move. What started as a low-key prediction is now being viewed as a potential power shift, with insiders suggesting this decision could redefine the Yankees’ identity and force the entire American League to adjust sooner than expected.

The New York Yankees haven’t done much during the offseason, but MLB rumors continue to swirl. New York has been […]

Cubs Predicted To Land Marquee Free Agent Starting Pitcher On Six-Year Contract

The Cubs are in the market for a top-of-the-rotation starting pitcher, and David Schoenfield of ESPN predicted them to land Framber Valdez, previously of the Houston Astros.

🚨 INSIDE NFL REVELATION: The Packers reportedly had a stunning opportunity to sign an all time great for just $5 million, yet chose to walk away without even making a free agent offer — a quiet decision that is now raising serious questions inside the fanbase and league circles alike. What seemed insignificant at the time is suddenly being revisited as a potential turning point, with insiders suggesting this missed move could have changed far more than anyone realized.

Green Bay missed an opportunity.