Mariners Rumors: Trade buzz with Red Sox is a pure rollercoaster ride

Much like the Seattle Mariners, the Red Sox are yet to make a big free agent move. Other than signing Aroldis Chapman to a one-year, $10.75 million contract and missing out on Juan Soto, they haven't been in the news for much else.

However, on the trade front, they just completed one of the biggest swaps of the offseason, sending four top prospects to the White Sox in exchange for lefty starter Garrett Crochet. While this is already a big upgrade to their rotation, it seems like they aren't finished just yet. In fact, the Mariners could be involved in the next step of their plan to improve their 2025 roster.

The most recent rumors were that Seattle turned down a deal that would have sent Triston Casas to the Mariners in exchange for one of the team's young starters. Now, it seems that Boston has shifted their gaze to eye the team's most experienced starter.

In a conversation on the Wyman and Bob podcast, Jon Morosi specified that he believed the most likely target would be Luis Castillo. Given the Mariners' unwillingness to part with the arms over which they have the most team control, it seems natural that Castillo would be a good backup plan. He's heading into the third year of a five-year deal with a vesting option in 2028, so he'll still be under contract for a few more years, but his fixed salary of just over $24 million could be an incentive for Seattle to ship him off.

Mariners Rumors: Red Sox trying to trade for one of Seattle's starters

Ultimately, this is all hearsay and speculation and some Boston writers have heard other thoughts on the situation. Some of the trusty insiders over there have shot down some of the early speculation, including the Casas buzz.

Alex Speier is a trusted Sox reporter for the Boston Globe and while he didn't deny the trade rumors, he did refute one specific scenario.

Of course, even this could be a redirection. In today's news cycle, it can be difficult to discern right from wrong and rumors from truth. Sources are rarely disclosed and front offices and players often devise their own games to shift certain market dynamics in their favor. Depending on who you ask on what day of the week it is, you could get a totally different answer on whether Castillo was actively being pursued by the Red Sox and what the return package for the Mariners would be.

If not Boston, there are other big market teams on the East Coast that could have their eyes on acquiring Luis Castillo. With the Winter Meetings now over, Jerry Dipoto and his crew of merry men and women could be waiting to execute a massive trade in the new year. The club's passivity during this week shouldn't necessarily be interpreted as a foreboding omen, but until they see some real impactful changes to the roster it wouldn't be surprising if fans started stirring.