Recap: In his second rehab start after undergoing Tommy John surgery, Nationals starting pitcher Jordan Zimmermann tossed three scoreless innings in Potomac's 7-4 win over Frederick at Harry Grove Stadium.
Zimmermann struck out five Keys batters and allowed one hit before being replaced by the Nationals' Adrian Alaniz, who tossed five no-hit frames with eight strikeouts.
Frederick starting pitcher Ryan O'Shea (5-4) suffered the loss after giving up six runs (five earned), seven hits and six walks in five innings. He collected two strikeouts.
Keys catcher Phil Britton contributed two RBIs in the defeat.