Morosi dives into idea of Mariners trading Castillo for Boston’s Casas

MLB Network’s Jon Morosi reported Wednesday that even after Boston traded for White Sox All-Star pitcher Garrett Crochet, the Red Sox were still wanting to acquire a pitcher from the Seattle Mariners – with the likely target being Luis Castillo.

Related: There’s smoke around a possible Mariners-Red Sox trade

That afternoon, Morosi joined Seattle Sports for his weekly conversation with Wyman and Bob, and he called a potential move sending Castillo to Boston for young, big first baseman Triston Casas a “reasonable idea” for the Mariners.

“If they make this trade, it is not only for Triston Casas, it is for Triston Casas and whatever else you can do with the money that Luis Castillo was going to make,” Morosi said. “So I think the Mariners are probably looking at it.”

While Morosi reported there was actual conversation between the Mariners and Red Sox on Wednesday during MLB’s winter meetings in Dallas, Seattle president of baseball operations Jerry Dipoto and general manager Justin Hollander’s public message throughout the meetings was that they are reluctant to trade a starter. Before resorting to something that Dipoto called “Plan Z” in September, more of the offseason would need to unfold. The markets would need to be more clear and, one could only assume, more teams in on the conversations. To that end, Alex Speier of the Boston Globe reported Wednesday afternoon that he was given the answer “No” from a source when asked if a Castillo-for-Casas deal had legs.

Still, Morosi believes the Mariners should be open to trading a starter.

“I want to reframe a bit of the the conversation around the Mariners and free agency,” Morosi said. “Because yeah, it’s a real thing. People will say hitting at T-Mobile (Park) is a challenge and it’s hard to attract top free agents, and that’s why the best free agent bat they could get last year was Mitch Garver, who struggled. … Well, you know what else is real? T-Mobile’s a great place to pitch, which is why pitchers who are trying to have a good bounceback year should want to sign there and pitch there. And the other piece is the Mariners have built for themselves a pretty good reputation about developing pitching. Own that.”

The Mariners have been no stranger to bounceback-candidate signings in Dipoto’s tenure, though with little success on the hitting side. A bounceback candidate in the rotation has not been needed in the recent past, but Morosi thought it was worth asking if the Mariners would be better if they added Casas plus a hitter like Jurickson Profar in free agency, then finding the right bounceback candidate to take the open rotation spot. Would the pitching environment, coaching and analytics be of benefit? Morosi believes it would put the Mariners in a better position.

“Bring in the pitching, and then if you eventually trade the pitching for bats, do it that way,” he said. “I think that we’re seeing it can be a frustrating thing for the Mariners to chase one free agent bat after another, only to hear in the end, ‘Well, Seattle is too far away from my home’ or ‘The ballpark’s too big.’ Forget about that. Develop the pitching, and then when the time is right like it is right now with Castillo, trade the pitching for the bats that you want.”

That would most likely require trading one of the Mariners’ other four starters who are all under club control. As Morosi said earlier, trading the 32-year-old Castillo for Casas, who will turn 25 next month, would be largely about the dollars. Per Spotrac, Castillo will make $24.15 million each of the next three seasons and has a vesting option for 2028 at $25 million. Casas, meanwhile, is estimated to make $800,000 in 2025 at 25 years old, won’t reach arbitration until after next season, and is under club control until after the 2028 season.

111 mph off the bat for Triston's 6th homer of the season! pic.twitter.com/kjYDCU4kqs

— Red Sox (@RedSox) May 16, 2023

Should that hypothetical trade happen, the question then would be what the Mariners could get for those dollars. Casas, who slashed .241/.337/.462 for an .800 OPS in 63 games this year, occupies the position that has perhaps the most robust market in free agency – certainly much more robust than the Mariners’ other two articulated needs, second base and third base. It would perhaps not be the the optimal first move for the Mariners.

In his weekly visit with Wyman and Bob, Morosi also gave a full rundown on Casas as a player and personality, listed a couple of options for the Mariners at second and third base, pointed out where the Mariners could have a leg up in the pursuit of star Japanese pitcher Roki Sasaki, and shared his thoughts on the Mets’ Juan Soto deal. The full conversation can be found in the podcast at this link or in the player near the top of this post.

More on the Seattle Mariners

• Lucky Mariners unexpectedly land very high 2025 MLB Draft pick
• Here’s who Mariners could take at No. 3 overall in the next draft
• The Mariners will have a strong pitch for Japanese star Roki Sasaki
• Salk: The three Mariners to watch as surprise trade candidates
• How the Seattle Mariners are being ‘very aggressive’ on trade market

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