Hassell is not in the lineup for Wednesday's game versus the Mets.
The Mets are sending lefty David Peterson to the hill, marking the second straight time the left-handed-hitting Hassell is absent from the lineup against a southpaw. Hassell had started against lefties each of the first five times the Nationals faced a lefty following his promotion from Triple-A Rochester on May 21, but Washington has less of a need for him to face same-handed pitching following the recent return of Jacob Young from the injured list.