Ray (oblique) threw a 15-pitch bullpen session Tuesday, Zach Buchanan of The Athletic Arizona reports.
Ray's follow-up MRI apparently revealed the southpaw's Grade 2 oblique strain is healing as expected, clearing the way for him to throw off a mound for the first time since landing on the disabled list at the end of April. The lefty tossed strictly fastballs in the session, but is expected to incorporate more breaking pitches the next time he throws off the mound. The Diamondbacks don't have a firm timetable for Ray's return, but it doesn't appear he'll be reinstated from the 10-day disabled list until mid-June at the earliest.