nn101394555295_image_982w Starting pitcher Danny Rosenbaum was traded to the Red Sox. (Photo by John McDonnell/The Washington Post)

The Nationals added depth behind the plate late Tuesday, acquiring 28-year-old Dan Butler from the Red Sox in exchange for left-handed starter Danny Rosenbaum, who made 28 starts for Syracuse in 2013 and four last season before undergoing Tommy John surgery. The deal, announced by the team Wednesday morning, was first reported by the Boston Globe’s Nick Cafardo.

Boston designated Butler for assignment last week, making him the unlucky extra in the Red Sox catching picture, pushed out to make room on the 40-man roster after the signing of reliever Craig Breslow. The Red Sox signed Butler as an undrafted free agent out of Arizona in 2009, and the 28-year-old made his Major League debut last August when veteran David Ross went down. But with mega-prospect Blake Swihart set to start the season at Class AAA Pawtucket and Christian Vazquez and Ryan Hanigan likely to find homes at Fenway, the organization was out of innings to give Butler at an appropriate level.

So the Nationals dealt Rosenbaum, a 27-year-old southpaw built around a devastating changeup that helped him post a 3.12 ERA in 121 minor league games with 498 strikeouts. He has yet to make an appearance in the major leagues, and with six years of minor league experience was due to be a minor league free agent after this season — so the deal gives the Nationals some return on their investment.

In Butler, Washington gains veteran insurance behind recently banged-up Wilson Ramos and Jose Lobaton. Sandy Leon would likely be the next man up should either of those two fall injured, but he is out of options and therefore not a guarantee to feature on the roster. Steven Lerud, who the Nationals signed earlier this week, could also be in the mix: The 30-year-old spent last season at Class AAA with the Braves, and has nine games of Major League experience with the Phillies, most recently in 2013.

Butler led all Triple A catchers with 54 assists in 2013, throwing out 30.5 percent of attempted thieves that season. Known for that defensive prowess and for being a strong contributor to the character of a clubhouse, his light-hitting history (career .256 hitter in the minors) is less important to the Nationals than the influence they believe he can have on their young pitchers. With 39 players currently on the 40-man roster, Butler could likely carve out a spot and may be a more flexible option than Leon should he do so.