Ahead of Thursday afternoon’s series finale in Toronto, the Boston Red Sox will reportedly place reliever Garrett Whitlock on the 15-day injured list due to right elbow inflammation, dealing a major blow to the backend of what has been the best bullpen in baseball in 2026. The move comes after interim manager Chad Tracy told reporters after Wednesday night’s loss that the 30-year-old, who had not pitched since Sunday's loss to the Athletics, was unavailable due to the injury. 

MassLive.com’s Chris Cottilo was first with the news that Whitlock would be headed to the IL. 

The 30-year-old Whitlock has been Boston’s main setup man ahead of All-Star closer Aroldis Chapman in 2026. In 44 innings pitched, Whitlock has posted a 2.05 ERA, holding opponents to a .203 batting average. 

This will mark the second trip to the injured list for Whitlock in 2026, as he spent 12 days on the IL with left knee inflammation. Since his return on June 9, Whitlock has been among the best relievers in baseball, posting a 1.11 ERA in 24.1 innings, the 18th-lowest mark among all qualified relievers. 

“It was kinda gradually getting that way, and it’s getting to a pretty good point (of discomfort),” Whitlock told Cotillo on Wednesday. “I don’t think there’s anything structurally wrong with it. Obviously, I’m sure there’s probably a lot of inflammation in there. My concern for the need for any drastic measures is very low,” he continued. 

As reported by Cotillo, reliever Greg Weissert will be recalled from Triple-A Worcester to replace Whitlock on the active roster. 

Weissert finds himself back with the big league club just five days after being sent to Triple-A on Friday afternoon to provide some reinforcements to the Boston bullpen after last Thursday’s 13-inning marathon against the Chicago White Sox. 

It’s been an up-and-down season for the 31-year-old right-hander. In 45.1 innings, Weissert has posted a 3.97 ERA; however, he’s been better of late, with a 3.30 ERA over his last 30 innings.

He has particularly struggled taking over in the middle of innings with runners already on base, allowing 13 of his 29 inherited baserunners to score, the third most among all relievers. He’ll likely find himself in some higher-leverage spots upon his return thanks to the injury to Whitlock. 

The Red Sox will look to avoid the four-game sweep at the hands of the Toronto Blue Jays and snap a season-long five-game losing streak in Thursday afternoon’s series finale North of the Border. Payton Tolle (7-6, 3.20 ERA) gets the start for Boston opposite future first-ballot Hall of Famer Max Scherzer (1-4, 7.25 ERA) for Toronto. First pitch is set for 3:07 p.m. ET.