When the Boston Red Sox selected Garrett Whitlock in the Rule-5 Draft in December 2020, he was a relative unknown. At the time he was selected, he hadn’t pitched since 2019, when his season was cut short due to a UCL injury. Despite only rising as high as Double-A Trenton, the Red Sox took a flier on a righty with good stuff.
Whitlock took the opportunity and ran with it. In his first season, he posted a 1.96 ERA in 73 1/3 innings and became a key piece of the Red Sox bullpen down the stretch. He was 1-0 with a 2.16 ERA in five postseason outings that season.
The following season, the Red Sox made the decision to move Whitlock to the rotation. With several pitches to use against both lefties and righties, as well as the ability to pitch multiple innings, the move made sense on paper. In practice, it was unsuccessful. Whitlock pitched well, but couldn’t stay on the field. From 2022 to 2024, he threw 168 1/3 innings and registered a 4.01 ERA. Finally, in 2025, he moved back to a full-time bullpen role.
The move paid dividends, as Whitlock put together his best season since 2021. In 62 appearances, he posted a 2.25 ERA while striking out 31.1% of the hitters he faced. His fastball velocity was tied for the highest in his career, and he didn’t spend any time on the injured list for the first time since his debut season.
“Moving to the bullpen allowed me to feel good all year, and I bounced back after throwing back-to-back days,” Whitlock said on MLB Network Radio.
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Red Sox manager Alex Cora stayed away from Whitlock on back-to-back days at the beginning of the year, but leaned on him heavily down the stretch. In the second half of the season, Whitlock was tied for the most appearances on the team with Greg Weissert and only allowed one earned run over 26 2/3 innings.
While the rotation experiment made sense on paper, Whitlock has found a role he thrives in in the bullpen. While Aroldis Chapman is the closer, Whitlock was often called upon to face the opponent’s best hitters. He’ll continue to fill that role in 2026 for the Red Sox and likely be used in a single-inning capacity for Team USA at the World Baseball Classic.
