Santiago tested positive for exogenous testosterone, a banned performance-enhancing substance, according to MLB.
The Mariners have traded right-hander JT Chargois and third-base prospect Austin Shenton for Castillo.
William Weinbaum ESPN
The Hall of Fame's Board of Directors announced Thursday it has unanimously denied Curt Schilling's request to be removed from the Baseball Writers' Association of America HoF ballot, so he will remain eligible for the 10th and final time in 2022. The Hall also announced the election of HoFers Craig Biggio, Tom Glavine & Ken Griffey Jr. to its Board, newly comprising 17 directors, including six HoF members (others: Cal Ripken Jr., Brooks Robinson & Ozzie Smith).
Here's our report card for every big move as the July 30 deadline approaches.
July 30 is approaching fast. Here's the freshest intel we're hearing, reaction to completed deals and what to know for every team.
Who is rising and falling on our list ahead of Friday's 4 p.m. ET trade deadline?
— Yuli Gurriel singled, doubled and homered to drive in three runs and lead the Houston Astros over the Seattle Mariners 11-4 on Wednesday.
The Seattle Mariners introduced new president of business operations Catie Griggs, whom they hope will help with the team's culture of diversity and inclusion.
The Astros have acquired relievers Kendall Graveman and Rafael Montero from the Mariners for third baseman Abraham Toro and reliever Joe Smith. A teary Graveman said he was shocked by the trade, and had assumed he would be sticking with the Mariners.
— Abraham Toro homered for Seattle against the team that traded him across the diamond during batting practice, but the Houston Astros held off a ninth-inning rally to beat the Mariners 8-6 on Tuesday night.
The Mariners acquired Tyler Anderson from the Pirates, who earlier Tuesday thought they had a deal with the Phillies for the left-handed starter only to see it fall through on medical review.
Jeff Passan ESPN
The Seattle Mariners are finalizing a deal to acquire left-hander Tyler Anderson from the Pittsburgh Pirates, sources tell ESPN. The Pirates thought they had a deal today for Anderson with Philadelphia, but it fell through on medical review. Seattle went and got him instead.
The Houston Astros have acquired Kendall Graveman from the Seattle Mariners. Who got the best of this move?
Jeff Passan ESPN
The Houston Astros have acquired relievers Kendall Graveman and Rafael Montero from the Seattle Mariners for third baseman Abraham Toro and reliever Joe Smith, sources tell ESPN. An intra-division deal that lands Houston one of the best relievers in MLB this year in Graveman.
The Seattle Mariners hired Catie Griggs as the club's new president of business operations on Tuesday. She replaces Kevin Mather, who resigned in February after video surfaced of him making derogatory remarks about some players and club operations.
— Dylan Moore hit a grand slam in the eighth inning to lift the Seattle Mariners to an 11-8 comeback win against the Houston Astros on Monday night.
— Catcher Tom Murphy turned toward the stands behind home plate, pumped his fist and seemed to try to scream in celebration above the din of noise emanating from the cheers of the home crowd.
— Struggling rookie Jarred Kelenic scored the winning run on Lou Trivino’s wild pitch in the bottom of the ninth, Mitch Haniger homered twice and the Seattle Mariners beat the Oakland Athletics 5-4 on Saturday night.
— Cal Raleigh and Luis Torrens hit back-to-back homers, Dylan Moore scored the go-ahead run on consecutive wild pitches and the Seattle Mariners beat the Oakland Athletics 4-3 on Friday night.
— Sean Manaea struck out a career-high 13 in seven strong innings, Ramón Laureano drove in two runs and the Oakland Athletics beat the Seattle Mariners 4-1 Thursday night in the opener of a 10-game road trip.
The trade deadline presents a conundrum for teams on the playoff bubble. Here's how our experts ranked them after Week 15.
— Austin Gomber pitched effectively for six innings after spending a month on the injured list, Dom Nunez hit a bases-loaded double in a five-run first and the Colorado Rockies beat the Seattle Mariners 6-3 Wednesday.
For some, the decision of whether to make a big move at the trade deadline or stand pat is pivotal. Here's our take on that choice for five clubs on the playoff bubble.