The Kansas City Royals acquired right-handed reliever John Schreiber from the Boston Red Sox on Saturday for right-handed pitching prospect David Sandlin.

Schreiber, 29, was a late bloomer whose best season came in 2022, when he posted a 2.22 ERA over 65 innings with a nearly 4-to-1 strikeout-to-walk ratio. He regressed slightly last year, with his walk and home run rates growing, but still struck out 53 over 46.2 innings with a 3.86 ERA. He will make $1.175 million this season and isn't a free agent until after the 2026 season.

With the free agent signings of Will Smith and Chris Stratton, plus a trade for Nick Anderson, the Royals have overhauled a bullpen that had the worst ERA in the American League last year at 5.23. Kansas City has been one of the most aggressive teams in baseball this winter, spending more than $100 million in free agency and signing star shortstop Bobby Witt Jr. to an 11-year, $287.8 million deal.

Boston had entertained trading from their bullpen all winter, discussing Schreiber, closer Kenley Jansen and setup man Chris Martin. In the soon-to-be 23-year-old Sandlin, they'll receive a right-hander with an above-average fastball and slider, plus a split-fingered fastball. An 11th-round pick in 2022, Sandlin finished his first full season with a 3.51 ERA in 14 starts between Low-A and High-A.

The Red Sox's minor league system has improved significantly in recent years, with Marcelo Mayer, Roman Anthony and Kyle Teel headlining one of baseball's better prospect groups. Their lack of pitching depth has been an issue new chief baseball office Craig Breslow wanted to address, and Sandlin -- who scouts believe has the stuff to be a big league starter -- helps address that.