The Athletics have placed starter Sonny Gray on the 15-day disabled list with a strained right trapezius, according to Susan Slusser of the San Francisco Chronicle. The club promoted left-hander Daniel Coulombe to take Gray's place.
Gray, 26, has struggled mightily this season, posting a 3-5 record and 6.19 ERA in nine starts for Oakland. His upper back issues may be the cause of his struggles, so he will likely aim to get fully healthy and re-work his mechanics during his DL stint.
It is currently unclear how long Gray will miss due to the injury, but previous recovery periods for pitchers with similar injuries have lasted about a month. That would mean Gray will likely return in late June, giving himself about a month to prove his health before the non-waiver trade deadline.
Oakland is expected to be a major player at this year's deadline, with Gray joining also-injured outfielder Josh Reddick, third baseman Danny Valencia and pitchers Rich Hill and John Axford as potential candidates for the A's.