Rumor: Red Sox Eyeing Mariners Starter

According to MLB Network’s Jon Morosi, the Boston Red Sox are targeting Seattle Mariners starting pitcher Luis Castillo. The Red Sox have already acquired ace pitcher Garrett Crochet from the Chicago White Sox. In 2024, Castillo sported an 11-12 record, a respectable ERA of 3.64, 175 strikeouts, and a WHIP of 1.169. The Mariners trading Castillo is becoming increasingly likely. MLB insider Mike Rodriguez stated that “it’s almost a certainty that he gets traded this offseason.” His go-to pitches are the fastball and slider. While 2024 isn’t an example of his strongest efforts due to a hamstring injury, Castillo remains an appealing trade target. The Dominican native owns the nickname ”La Piedra,” which in Spanish means ”The Rock.”

The Red Sox, even after the Crochet trade, are working to acquire one of the Mariners’ starting pitchers, sources say. @MLBNetwork @MLB

— Jon Morosi (@jonmorosi) December 11, 2024

Rumor: Red Sox Targeting Mariners Starter Luis Castillo

The Red Sox’s biggest offseason need was to pick up a quality starter, but that doesn’t mean they have to limit themselves to just one. Boston is one rumored landing spot for Castillo, and he has many other suitors, such as the Chicago Cubs, New York Yankees, Philadelphia Phillies, and the New York Mets. Seattle owes him $70 million over the next three years and he projects to get just over $70 million in terms of field value. According to Spotrac, Castillo will earn $22,750,000 in his base salary, while earning a total of $24.15 million in 2025.

Baseball Savant shows Castillo with solid rankings concerning his Pitching Run-Value (86th percentile), Fastball Run-Value (93rd percentile), and Breaking Run-Value (82nd percentile). Following the $218 million signing of Max Fried with the Yankees, the offseason and free agent market continues to heat up. Castillo’s remaining salary doesn’t compare with the remainder of the starting pitching market. Castillo would make a suitable starter for the Red Sox as he’s sported a 5.6 fWAR in his last 63 starts. Also, he hasn’t pitched fewer than 150 innings through an entire season. His fastball was dominant and impressive in 2024 and tied for sixth-best in MLB. Castillo’s contract is also cost-effective, making him an even more appealing acquisition for the Red Sox.