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Who Will Step Up for Boston Red Sox in Garrett Whitlock’s Absence?
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- Who Will Step Up for Boston Red Sox in Garrett Whitlock’s Absence?
Entering Thursday's series finale in Toronto, the Boston Red Sox bullpen has posted a 2.97 ERA in 451 innings of work, a mark good for the lowest in baseball this season. However, the elite Boston relief group took a massive hit on Thursday afternoon when the team placed setup man Garrett Whitlock on the 15-day injured list with right elbow inflammation.
The 30-year-old Whitlock has been one of the best setup men in baseball, bridging the gap to All-Star closer Aroldis Chapman by posting a 2.05 ERA and holding opponents to a .203 batting average in 44 innings of work. He is tied for the eighth-most holds in the sport with 21.
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The absence of Whitlock puts a lot of pressure on the rest of the Red Sox pen, particularly these three relievers:
Justin Slaten
Jul 17, 2026; Boston, Massachusetts, USA; Boston Red Sox pitcher Justin Slaten (63) pitches during the eighth inning against the Tampa Bay Rays at Fenway Park. Bob DeChiara-Imagn Images
It has been an up-and-down 2026 season for the 28-year-old right-hander, who, at times, has looked unhittable coming out of the bullpen. Slaten has allowed 16 earned runs on 35 hits across 31.1 innings, good for a 4.60 ERA; however, eight of his 16 earned runs allowed came in two blow-up appearances. Since July 1 though, he has returned to form, posting a 2.19 ERA in 12.1 innings as the Red Sox have gone 12-2 in games he's appeared in.
He, along with Tyron Guerrero, will share the bulk of the work as interim manager Chad Tracy's highest-leverage right-handed arms in Whitlock's absence.
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Tyron Guerrero
The 35-year-old flamethrower has been a revelation for Boston after having not pitched in the big leagues since 2019. Guerrero has posted a 3.19 ERA in 31 innings of work in his return to the majors, a number that was only recently inflated thanks to a blowup appearance in Wednesday night's 6-4 loss to Toronto .
Aug 5, 2026; Boston, Massachusetts, USA; Boston Red Sox pitcher Tyron Guerrero (41) pitches against the Chicago White Sox during the seventh inning at Fenway Park. Eric Canha-Imagn Images
After walking 13.6 percent of the batters he faced in his first 105 innings at the big league level, Guerrero has walked only five batters in 2026, while striking out 34. The 35-year-old will have to flush Wednesday's blowup and get back to form, as he'll be relied on heavily in Whitlock's absence.
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Erik Miller
The 28-year-old left-hander has been the missing piece to the Red Sox bullpen puzzle since arriving from San Francisco ahead of the trade deadline , giving Tracy a situational high-leverage left-hander ahead of Chapman.
Aug 9, 2026; Boston, Massachusetts, USA; Boston Red Sox pitcher Erik Miller (67) pitches during the first inning against the Athletics at Fenway Park. Bob DeChiara-Imagn Images
In four appearances since the trade, Miller has allowed only one unearned run on four hits while striking out eight and walking only one. Like Guerrero, Miller had major control problems, walking 15.3 percent of the batters faced during his time with San Francisco. However, in his brief time in Boston, he has already cut that number down to 5.1 percent.
He'll likely be leaned on more heavily in late-inning spots with Whitlock on the shelf.
Luckily for Tracy, Chief Baseball Officer Craig Breslow has built incredible depth in the bullpen; however, the loss of Whitlock is still a major one.
