BOSTON — The Twins bullpen has been the biggest culprit in the team's decent from back-to-back AL Central champions to a last-place team.

The bullpen ERA stands at 4.76 entering the season's final six weeks, the worst by a Twins pitching staff since 1996. With 277 runs against already, Twins relievers are on pace to give up 362 this season, shattering the franchise record of 328 by the 2018 bullpen. They have already walked as many batters as the 2019 staff did in a full season, and they figure to threaten the franchise mark for home runs, too.

This from a relief staff that posted the fourth-best ERA in the American League last year.

Oh, wait — that wasn't this bullpen. Which makes the Twins' plight all the more regrettable.

"It's definitely the most challenging aspect of team-building, for sure," Twins President of Baseball Operations Derek Falvey said Monday. "Just in terms of keeping things, year-to-year, as stable as you can — it's so difficult to know with relief pitchers. In '19 and '20 we had good bullpens, both of those years. Those guys all pitched really well, and our team reflected that in overall performance. Obviously, this year we had a few situations that didn't go as well."

Making that more painful, however, is the performance of the players the Twins chose to jettison, or at least not bring back:

  • Sergio Romo, allowed to leave for Oakland as a free agent after pitching only 20 innings last year, has rebounded with his best season in five years. At 38, Romo looked old in April, giving up nine runs in his first 6⅓ innings. Since then? He has given up only seven more, posting a 1.49 ERA since April 25.
  • Zack Littell, outrighted off the 40-man roster last September, signed a minor league deal with the Giants and has turned into a reliable middle-inning reliever, giving up only one run in August and posting a 2.84 ERA for the season.
  • Tyler Clippard, who signed with the Diamondbacks after his one-year deal ran out, feared his career was over when he suffered a shoulder capsule sprain in April. But he returned in July and has saved four games in five chances for Arizona, posting a 3.00 ERA.
  • Trevor May received a $16 million, two-year contract from the Mets, and though he's had home run problems, he has still struck out 64 batters in 48 innings in a setup role, plus four saves and 11 holds.
  • Matt Wisler was not retained last December despite a 1.07 ERA in 18 games in 2020. He signed with San Francisco but struggled with a 6.05 ERA, but he has a 1.98 ERA in 24 games since being traded to Tampa Bay in June.

"I'm happy for those guys, I really am. We had conversations with a lot of them, would have liked to bring them back. There was a reason we brought them in the previous years," Falvey said. "But sometimes when a pitcher you've been talking with reaches a decision, that's the direction you go. That's the decision you have to make."

The Twins' most notable bullpen addition was Alexander Colome, who signed a contract that pays him $5 million this year and can be worth an additional $5.5 million if both sides decide to exercise an option for next year. Colome's Win Probability Added, a statistic that measures a player's actual effect on winning games, "was horrific" in April, when he blew three save chances and absorbed three losses in the Twins' first 21 games. But until his last outing in Target Field, Colome had ranked among the top three players in baseball in WPS since the All-Star break.

The Twins also signed former Angels closer Hansel Robles to a one-year deal worth $2 million. The righthander earned 10 saves with the Twins, but he posted an 11.12 ERA over his final 12 appearances before being dealt to the Red Sox at the trade deadline.

"The volatility of bullpens is real. The number of [relievers] who pitch consistently at a high level over a two- to three-year period across baseball is a surprisingly low number, relative to what you try to accomplish in building that pen each year," Falvey said. "When it goes well, you usually end up with a pretty good season and you keep yourself in a lot of games. And for us, it's been a lot more up and down than we'd hoped."