In a surprising turn of events, the Baltimore Orioles have acquired right-hander Luis F. Castillo from the Seattle Mariners in a cash deal, marking a new chapter for the 30-year-old pitcher. This transaction, which took place on Wednesday, May 7, 2025, comes just a day after the Mariners designated Castillo for assignment.
Castillo's journey in the major leagues has been a rocky one. He made two starts for Seattle at the beginning of the season but struggled significantly, posting a 0-0 record with a 7.71 ERA. Over seven innings, he struck out five batters while walking seven, indicating control issues that contributed to his early-season woes. Following those outings, he was optioned back to the minors.
In the minors, Castillo continued to face challenges. He made four starts for Triple-A Tacoma, where he recorded an 0-1 record and a 5.02 ERA. Despite striking out 12 batters and walking five in 14 1/3 innings, he surrendered eight runs, which further complicated his path back to the big leagues.
Prior to his time with the Mariners, Castillo had limited major league experience, having pitched in just three games for the Detroit Tigers in 2022. During those appearances, he threw 3 2/3 innings of shutout baseball, but his time in the majors was short-lived. After spending the next two seasons in Japan, where he posted a respectable 2.96 ERA over 94 1/3 innings for the Orix Buffaloes, Castillo returned to the MLB with hopes of revitalizing his career.
The Mariners' decision to designate Castillo for assignment was influenced by their recent acquisition of outfielder Leody Taveras from the Texas Rangers. This move left the Mariners with only one player named Luis Castillo: the three-time All-Star right-hander Luis M. Castillo. The Orioles, in turn, opened a spot on their 40-man roster for Castillo by designating left-hander Walter Pennington for assignment.
Pennington, who is 27 years old, never made an appearance for Baltimore and struggled significantly in the Orioles’ farm system, recording a 0-2 record with a staggering 45.00 ERA in just two games, including one start. He made his major league debut last year, combining for a 1-0 record and a 3.00 ERA in 16 games for the Kansas City Royals and Texas Rangers. However, his recent performances have raised concerns about his ability to contribute at the big league level.
As Castillo joins the Orioles, he will be optioned to Triple-A Norfolk, where he will work alongside other depth starters such as Brandon Young and Chayce McDermott. With a fastball and sinker sitting in the 91-92 MPH range, Castillo possesses the potential to develop into a reliable option for the Orioles, particularly if he can refine his control and performance on the mound.
This acquisition is not just about adding depth; it represents Baltimore's commitment to bolstering their pitching staff as they navigate the competitive landscape of the MLB. Castillo's experience in Japan and his previous major league outings provide a unique perspective that could benefit the Orioles as they look to improve their overall performance.
While Castillo's journey has been fraught with challenges, this new opportunity with the Orioles could serve as a turning point in his career. The organization will be watching closely to see how he adapts to his new surroundings and whether he can find success in the minors before making a return to the majors.
As for the Mariners, the decision to part ways with Castillo signals a shift in their roster strategy, particularly following the acquisition of Taveras. They will now look to build a stronger team with the remaining players on their roster, including the other Luis Castillo, who continues to be a cornerstone for the franchise.
In the coming weeks, fans will be eager to see how Castillo performs in Triple-A and whether he can work his way back to the big leagues. The Orioles will be hoping that this move pays off, providing them with a much-needed boost in their pitching rotation as they aim for a successful season ahead.
