Melvin is unsure of an expected recovery time.
That leaves Stephen Vogt and Bryan Anderson as the only healthy catchers on the A's roster, with Josh Phegley also down with concussion symptoms.
• Right-hander Sonny Gray experienced hip soreness during his six-inning outing against the Giants on Friday night and Melvin said Saturday, "We'll give it some time and see how he feels in the next couple of days before we make a decision on whether he starts or not."
Jane Lee is a reporter for MLB.com. Read her blog, Major Lee-ague, and follow her on Twitter @JaneMLB. This story was not subject to the approval of Major League Baseball or its clubs.