Instant Grade: Red Sox Land Lefty Steal in Danny Coulombe

There has been chatter for months at this point about how the Boston Red Sox needed to add another left-handed reliever.

They reportedly did just that on Thursday night. The Athletic's Ken Rosenthal reported on Thursday night that the Red Sox are in agreement on a deal with left-handed reliever Danny Coulombe.

"Free-agent left-handed reliever Danny Coulombe in agreement with Red Sox on one-year, major-league contract, source tells The Athletic.

Free-agent left-handed reliever Danny Coulombe in agreement with Red Sox on one-year, major-league contract, source tells @TheAthletic
— Ken Rosenthal (@Ken_Rosenthal) March 12, 2026

There have been reports connecting Boston to Coulombe, including from MassLive.com's Chris Cotillo, going all the way back to December. Now, with two weeks to go until Opening Day, Boston gets a steal.

Let's dive in with an instant grade on the deal.

Red Sox's Instant Grade For Danny Coulombe Signing: A+

Aug 26, 2025; Arlington, Texas, USA; Texas Rangers relief pitcher Danny Coulombe (54) throws during the ninth inning against the Los Angeles Angels at Globe Life Field. Mandatory Credit: Kevin Jairaj-Imagn Images | Kevin Jairaj-Imagn Images

It took a while, but the Red Sox are bringing a big-time hurler to town. Coulombe has not finished a season with an ERA above 2.81 since 2021. He hasn't finished a season with an ERA above 3.67 since 2018. Overall, he has a 3.35 ERA across 343 total big league appearances. In 2025, he logged a 2.30 ERA across 55 total appearances with the Minnesota Twins and Texas Rangers.

The Red Sox's bullpen already looked good, now it's even more lethal.

The Athletic's Jen McCaffrey reported earlier in the week that there were six locks in the bullpen already.

"With less than three weeks until Opening Day, six relievers in Aroldis Chapman, Garrett Whitlock, Greg Weissert, Justin Slaten, Zack Kelly and Jovani Morán are in line to have spots in the bullpen," McCaffrey wrote. "That leaves two spots open, and Cora named five pitchers who have intrigued him in camp: right-handers Tayron Guerrero, Noah Song, Kyle Keller and Seth Martinez, and lefty Tyler Samaniego."

That's a good group on paper. Now, it will be a bit more even with Coulombe coming to town. With one more seemingly open, imagine if Kutter Crawford could be ready to roll on Opening Day? The group is already lethal with Coulombe coming to town. If the Red Sox could then put Crawford or Patrick Sandoval in the group as well, this very well could be the best bullpen in baseball. A-plus move by Boston.