Left-hander Brett Mooneyham will start for Single-A Potomac on Thursday, weather permitting. Mooneyham was 10-3 with a 1.94 ERA in 17 starts with Single-A Hagerstown.
Johansen, the Nats’ top pick in the June draft, is scheduled to start for Hagerstown on Friday. Johansen, a second-round selection, was 1-1 with a 1.06 ERA in 10 starts with the Doubledays.
Voth, a fifth-round pick in June, split time with the Gulf Coast League Nationals and Auburn. He made seven starts with the Doubledays and was 2-0 with a 1.47 ERA.
As previously reported, Giolito will start Wednesday for Auburn.