Per the team's press release:
WASHINGTON NATIONALS OUTRIGHT KORY CASTO AND MIKE O’CONNOR TO TRIPLE-A, PLACE TERRELL YOUNG ON 15-DAY DISABLED LIST
The Washington Nationals announced that infielder Kory Casto and left-handed pitcher Mike O’Connor have cleared waivers and been outrighted to Syracuse of the Triple-A International League. The club also placed right-handed pitcher Terrell Young on the 15-Day Disabled List, retroactive to March 27, with right shoulder inflammation.
Nationals Assistant General Manager and Vice President of Baseball Operations Mike Rizzo made the announcements.
This pretty much ensures that Wil Nieves and Josh "The" Bard will both be on the opening day roster.
It'll be a short stay for one of them though, as they'll have to make room for Jordan Zimmermann on April 19.
