The Washington Nationals activated recently-acquired lefty Matt Thornton to their 25-man roster this afternoon, the team announced. The Nationals had claimed Thornton off waivers from the New York Yankees on Tuesday.

Thornton adds another left-hander to a bullpen that already features Jerry Blevins and Ross Detwiler from the south side. Aside from a strong outing against the Phillies on Saturday, Blevins has struggled as of late, and Detwiler is used primarily as a long reliever, so Thornton gives manager Matt Williams a reliable situational left-handed option while Blevins continues to work out of his slump on the mound.

The acquisition also allows Williams to do more match up work with his bullpen, a luxury that was not nearly as available to him previously. But while Thornton had been used almost exclusively as a lefty-specialist with the Yankees this season, he's also proven over the course of his career that he can handle right-handed hitters. This season, right-handers actually have had less success against Thornton (.243) than lefties (.250).

To make room for their new bullpen arm, the Nationals optioned right-hander Blake Treinen to AAA Syracuse. Treinen spent time as both a starter and a reliever in his time with the big-league club, pitching to a 2.53 ERA in five starts and 11 total appearances. 

Thornton is owed $1 million through the end of this season, and will also be owed $3.5 million in 2015. So unlike most waiver acquisitions, Thornton will actually be around for the foreseeable future. He is available tonight as the Nationals take on the New York Mets in the second game of a three-game set.