The Nationals announced Wednesday that Thompson is dealing with an elbow injury and will be shut down from throwing for at least the next two weeks, Mark Zuckerman of MASNSports.com reports.
The right-hander apparently suffered the injury over the winter, and his availability for Opening Day is now in question. Thompson made a career-high 51 appearances for the Nationals last season but struggled to a 5.50 ERA, 1.56 WHIP and 44:22 K:BB over 54 innings, so he's hardly guaranteed to make the roster even if fully healthy.