Seattle Mariners Bolster Bullpen with Signing of Brendan White

The Seattle Mariners have added experienced bullpen depth by signing 27-year-old right-hander Brendan White, according to an announcement from the Lancaster Stormers. White spent six seasons in the Detroit Tigers organization before finishing 2025 in independent baseball, and the Mariners see him as a potential contributor to their Triple-A and eventual MLB pitching corps.

White was drafted in the 26th round of the 2019 MLB Draft out of Siena College. He climbed Detroit’s minor-league system and made his MLB debut in 2023, appearing in 33 games and logging 40 2/3 innings with a 5.09 ERA. His season included 44 strikeouts against 15 walks, with a four-seam fastball averaging 94-95 mph and a mid-80s breaking ball that he relied on heavily.

Injuries and inconsistency hampered White in 2024 and 2025. He struggled with command and was removed from Detroit’s 40-man roster before later returning on a minor-league deal. His time at Triple-A Toledo in 2025 saw a 7.24 ERA over 32 1/3 innings, with a significant drop in strikeout rate and opponents scoring more than seven runs per nine innings. Detroit released him midseason.

Following his release, White signed with the Lancaster Stormers, pitching 9 2/3 innings with mixed results, allowing six runs while issuing multiple free passes. The Mariners’ signing offers him another chance to reestablish himself in affiliated baseball and contribute to a team focused on pitching depth.

1. Career Overview and MLB Experience

Brendan White’s journey to the Mariners highlights both resilience and the unpredictable nature of professional baseball. Drafted in 2019 from Siena College, he steadily rose through Detroit’s minor-league system before making his MLB debut in 2023. During his rookie season, White appeared in 33 games for the Tigers, demonstrating an ability to miss bats with a 25% strikeout rate. His four-seam fastball and breaking ball combination allowed him to get through innings effectively, though he issued walks at an 8.5% rate. Overall, he showed promise as a mid-rotation or bullpen option at the major-league level. White’s performance in 2023 reflected both potential and areas for improvement. Command and consistency were primary concerns, but his experience facing major-league hitters provided a foundation for future growth. This prior MLB experience is valuable for the Mariners, as they seek to maintain depth in the bullpen and provide potential call-up options in case of injuries or rotation adjustments.

2. Struggles and Independent League Stint

The 2024 and 2025 seasons proved challenging for White. Injuries limited his availability and affected his mechanics, resulting in diminished command and effectiveness. After being non-tendered by Detroit, he rejoined the organization on a minor-league deal, only to struggle at Triple-A Toledo. Over 32 1/3 innings at Toledo, White’s ERA ballooned to 7.24, and his strikeout rate fell to 17%. Opponents scored over seven runs per nine innings, signaling a significant drop from his earlier MLB form. These struggles ultimately led to his midseason release. Seeking to continue his career, White signed with the Lancaster Stormers in the Atlantic League. In 9 2/3 innings there, he allowed six runs while issuing six walks and hitting four batters, demonstrating the challenges of regaining form in independent baseball. Despite these setbacks, White’s persistence and prior MLB experience make him a candidate for teams like the Mariners looking to develop pitching depth. The minor-league contract gives him a chance to rebuild his value and prove he can contribute at a high level again.

3. Opportunity with the Mariners

The Mariners are known for emphasizing pitching depth, and White’s signing aligns with that strategy. While he will likely begin the season with Triple-A Tacoma Rainiers, he has an opportunity to work his way back onto a major-league roster. Seattle’s bullpen rotation could benefit from a right-handed option with prior MLB experience. White’s mix of fastball velocity and breaking ball movement provides the tools needed to contribute in late-inning situations if he regains command. Spring training will be crucial for White to demonstrate readiness, rebuild confidence, and adapt to the Mariners’ pitching philosophy. Coaches will closely monitor his performance to determine how he fits into both the Triple-A and potential MLB plans. If successful, White could offer Seattle flexibility and depth in 2026, providing a reliable arm behind established relievers while also mentoring younger pitchers in the organization.