Nationals reliever Casey Janssen will undergo an MRI on his right shoulder, James Wagner of the Washington Post reports. According to Wagner, Janssen reported some abnormal soreness and had trouble getting loose in his last outing on Monday against the Yankees.
Janssen is no stranger to shoulder injuries, as they have nagged him for most of his career. Per Baseball Prospectus, he has had surgery on his shoulder twice: in March 2008 for his labrum, and in November 2012 for A/C joint spurs. He also spent a month and a half on the disabled list last year due to lower back issues. Over 45 2/3 innings with the Blue Jays last season, he finished with a 3.94 ERA and a 28/7 K/BB ratio.
Wagner notes that if Janssen needs to go on the disabled list, the Nationals could turn to Blake Treinen. Treinen made seven starts and eight relief appearances for the Nationals last season, compiling a 2.49 ERA and a 30/13 K/BB ratio in 50 2/3 innings.