Clay was designated for assignment by the Nationals on Friday, Matt Weyrich of NBC Sports Washington reports.
Clay was recalled from Triple-A Rochester on Monday and he registered one out in Wednesday's contest while also walking a batter and hitting another. The move opens a spot on the 40-man roster for Mason Thompson (biceps), who was activated from the 60-day injured list Friday. Clay will either be claimed by another team, report to Triple-A Rochester or be released outright.