Casey Janssen to have a MRI on right shoulder

VIERA, Fla. - Right-hander Casey Janssen will have a MRI on his right shoulder tomorrow, Nationals manager Matt Williams said Sunday afternoon.

"He's having a little trouble getting loose, so we're gonna have a test done on that," said Williams. "The last time out, he started to feel it. He had a little issue getting as loose as he wanted to get."

Janssen last appeared in Monday's game, when he pitched the sixth inning. He gave up a two-run homer to Yankees center fielder Chris Young. For the spring, Janssen has allowed three runs on six hits with two walks and five strikeouts in six innings. He's given up two homers, one to Young and one to Marlins slugger Giancarlo Stanton.

Williams said he will provide an update on the test results on Janssen's throwing shoulder after tomorrow's game against the Cardinals.

Janssen was expected to take over the eighth-inning relief role vacated when right-hander Tyler Clippard was traded to Oakland. Now the back half of the Nats bullpen is in doubt along with Janssen's availability with opening day just eighth days away. Closer Drew Storen has pitched just twice this spring, undergoing surgery to remove the hook of the hamate bone in his left (non-throwing) hand on March 13.

"Relievers are different because they don't need as much time," said Williams. "But I want to make sure (Janssen is) feeling good about it and he's able to do everything he wants to do, so we'll see what the tests reveal."

It's not the first time Janssen has experienced problems with his right shoulder. He had minor surgery to repair the right AC joint in November 2012. And last year, more discomfort in the shoulder forced a MRI early in spring training with the Blue Jays. That test was negative and Janssen returned to the mound a few weeks later.

"Generally, it's in his lat," said Williams. "So it's not something that's normal soreness for him, so we'll get a picture of it and see."

Janssen, 33, came to Washington from Toronto, where he spent the first 10 years of his professional career after being drafted in the fourth round in 2004. From 2011-13, he was 11-2 with a 2.46 ERA while appearing in 173 games with 58 saves and 170 strikeouts.

However, 2014 was a bit of a roller coaster for the veteran right-hander. Before the All-Star break, Janssen was 3-0 with a 1.23 ERA in 23 games with 14 saves. But during the break, he experienced a rough bout with food poisoning while on a trip to the Dominican Republic and could never return to proper form. His ERA shot up to 6.46 in the second half.

Janssen was originally on a list of pitchers scheduled to face the Mets in yesterday's game.