Boston sent 25-year-old catcher Jhon Nunez to Detroit in exchange for 26-year-old left-handed relief pitcher Matt Hall.
Nunez, who will join the Tigers' major league camp in Spring Training, had a strong season in Double-A last year. He posted .746 OPS in 232 plate appearances, far above his career mark of .683 in the minors.
As for the Red Sox, they're getting a reliever who has struggled to find his stuff at the major-league level. Since he debuted in 2018, Hall has posted an appalling 9.48 ERA in 31.1 innings of relief work.
His curveball spin rate ranked in the 96th percentile in 2019, however. The high spin rate is similar to that of other Red Sox relief acquisitions from the past few years, such as Colten Brewer, who ranked in the 90th percentile last year.
It gives both teams something that they're in need of. The Tigers get some minor-league catching depth with some potential upside, and the Red Sox get some much-needed relief depth.