According to Nationals manager Dave Martinez, Aaron Barrett underwent surgery on his right knee this past week and has returned to camp.
Barrett said he felt something after throwing in early February and simply had to “get it cleaned up.” The 33-year-old was looking to make the Nationals as a non-roster invitee, but the odds are stacked against him at the moment. The right-hander has a career 4.02 ERA, 2.88 FIP, and 10.46 K/9 in 74 career innings, but has thrown just 3.3 over the past two seasons.