The Boston Red Sox bullpen has been a standout all season. With Aroldis Chapman anchoring as the league’s most dominant closer and Garrett Whitlock excelling as the setup man, the duo has been exceptional.
But it hasn’t just been them, every member of the bullpen has contributed effectively, helping the Sox finish the season with the second-best bullpen ERA at 3.47. While a postseason berth isn’t guaranteed yet, Boston still controls its destiny over the final two series. The bullpen will be crucial in these games, aided by the expanded September roster, which allows the team to carry an extra pitcher. However, when the playoffs begin, the roster will shrink back to 26 players, meaning one pitcher will have to stay in Fort Myers, ready but inactive.
Currently, the bullpen features five left-handed pitchers and four right-handers. It’s likely all four righties, Whitlock, Zack Kelly, Greg Weissert, and Justin Slaten will keep their spots. Chapman, Steven Matz, and Justin Wilson are also expected to remain due to their performance and the roles they fill.
Another key factor for the playoff bullpen will be the shortened starting rotation. With extra rest days built in for travel, the Sox could rely on just four starters, freeing up an additional bullpen arm. That would give them nine possible relievers, though eight spots are probably already decided. The final roster spot is expected to come down to three candidates: Payton Tolle, Chris Murphy, and Kyle Harrison.
Which lefty reliever should remain with the Red Sox for their hopeful postseason run?
Payton Tolle
The rookie had a sensational debut, going toe-to-toe—and mostly coming out on top—against probable NL Cy Young favorite Paul Skenes. Since that first outing, though, things have been more uneven. In his second start, Tolle gave up five earned runs over just three innings, followed by two runs in two innings in his third start, prompting a move to the bullpen. His first relief appearance was solid, but his second—his first high-leverage opportunity—didn’t go as well.
The Red Sox believe his elite fastball can be highly effective in short bursts, though he has struggled with command at times. To earn a postseason spot, he’ll need at least one more strong performance, but for now, he doesn’t yet seem ready for the spotlight.
Chris Murphy
Since returning from Tommy John surgery, Chris Murphy has proven to be a reliable multi-inning reliever. He’s been effective against both left-handed and right-handed hitters, limiting lefties to a .619 OPS and righties to .645. September has been a bit rougher, though, as he’s issued seven walks and allowed seven hits across seven appearances. The Red Sox have mostly deployed him in mop-up situations this month—when games are out of hand—but that type of role can still be valuable in the postseason.
Kyle Harrison
Kyle Harrison is the most versatile of the three candidates. Although he’s only made two appearances for Boston, both have been impressive. His first relief outing was highly promising, while his six-inning start in the second appearance demonstrated why the Red Sox were interested in him. Harrison offers the team flexibility as both a multi-inning reliever and a potential spot starter in the playoffs. The main question, however, is whether Boston would choose him with so little experience over the other two options.
It’s likely the Red Sox will lean on Chris Murphy to start. He has the most experience among the trio and can provide multiple innings if a game gets out of hand, preserving the rest of the bullpen. Tolle remains too unproven to be trusted in high-stakes postseason action, while Harrison, as a starter, would probably begin the playoffs on the taxi squad in Fort Myers, staying stretched out in case of injury. Murphy has proven himself this season as a dependable option and could play a key role in October.
