The Nationals optioned Palmquist to Triple-A Rochester following Wednesday's game against the Phillies.
Palmquist gave up one earned run in 3.1 innings while making his season debut as the Nats' opener Wednesday. Now that he's fulfilled his duties with the big club, he'll head back to Rochester, where he's posted a 3.27 ERA and 0.73 WHIP across 11 frames since joining the organization in May.