Red Sox's Slumping Flamethrower Is Sneaky X-Factor In Boston's Playoff Goals

Mar 27, 2025; Arlington, Texas, USA; Boston Red Sox pitcher Justin Slaten (63) reacts after winning the game in the ninth inning against the Texas Rangers at Globe Life Field. Mandatory Credit: Tim Heitman-Imagn Images Tim Heitman-Imagn Images

Red Sox's Slumping Flamethrower Is Sneaky X-Factor In Boston's Playoff Goals

Originally posted on Boston Red Sox on SI
By Jackson Roberts | Last updated Sep 11, 2025 12:00 PM ET

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Justin Slaten's return from the injured list was hailed as a potential saving grace for the Boston Red Sox.

Slaten, the second-year relief pitcher who missed three months with a neck and shoulder issue, returned to action after a dominant rehab stint that suggested he could quickly resume high-leverage duties in a depleted bullpen. Instead, he's been getting lit up with alarming consistency.

Slaten took the ball with a 3-2 lead in the fifth inning of a bullpen game on Wednesday and quickly allowed the Athletics to load the bases on two loud hits and a walk. He was replaced after just 10 pitches, but two of his inherited runners crossed the plate, dramatically swinging the win probability in an eventual 5-4 defeat.

Red Sox need old Slaten back as fast as possible

Wednesday was the continuation of an unfortunate trend for Slaten. In 5 1/3 innings since returning from the injured list, he's given up seven earned runs on a staggering 12 hits, and when you watch him pitch, it's clear that he's searching for consistency on virtually all of his pitch types.

Slaten has been one of the most dependable Red Sox relievers at several points during the last two seasons. He put together a dominant April that was masked by one blow-up outing against the Baltimore Orioles, and it looked as though he'd be the primary setup man for closer Aroldis Chapman, a role eventually claimed by the sensational Garrett Whitlock.

In a perfect world, though, Slaten would be the third man on the totem pole for the playoff push behind Whitlock and Chapman. There's an argument to be made right now that he's not even fourth or fifth, as his season ERA has jumped to 5.02 through 28 2/3 innings.

Slaten's fastball, cutter, sweeper, and curveball are all plus pitches when he's tunneling them effectively. Since his return from the injured list, the fastball has sat about one mile per hour slower than usual, the cutter is getting hit hard, and the curveball isn't landing.

Boston doesn't have many other right-handed options to turn to in the bullpen. It's Slaten, Greg Weissert, and Zack Kelly as depth behind Whitlock the rest of the way. If the former can't get his act together, Boston's stay in the postseason might be a short one.

This article first appeared on Boston Red Sox on SI and was syndicated with permission.

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