The Nationals placed Irvin on the 15-day injured list Sunday due to a right shoulder strain.
Irvin suffered the injury during his start Saturday in Atlanta, but the right-hander indicated that an MRI didn't show anything overly concerning, adding that his diagnosis was the "best news we could have heard," per Mark Zuckerman of NatsJournal.com. Manager Blake Butera echoed those sentiments, telling Kyle Williams of TheBanner.com that he envisions a minimum stay on the shelf for the 29-year-old. After tossing five no-hit, scoreless innings before departing Saturday, Irvin lowered his ERA to 5.23 for the season.