The A's called on Rodriguez to start the eighth on Sunday, but he faced only two batters, departing with one out during an at-bat against Jordy Mercer. A team trainer and manager Bob Melvin visited the mound and removed the righty after a brief conversation. He was seen trying to stretch out his right arm prior to their visit.
Melvin said there was no indication anything was wrong with Rodriguez's shoulder prior to Sunday's outing.
Rodriguez is 2-0 with a 4.24 ERA in 33 appearances this year, and had allowed 12 runs in his last seven games entering Sunday. Melvin said Rodriguez worked in the bullpen this week to sort through some of his struggles and it appeared he had "better stuff" Sunday before the injury.
Oakland already lost one reliever in the past week, placing Sean Doolittle on the disabled list Thursday with a strained left shoulder after an MRI showed labrum inflammation. The A's are in the midst of playing 20 straight games without an off-day, and have now lost four straight.
Mark Chiarelli is a reporter for MLB.com based in the Bay Area. This story was not subject to the approval of Major League Baseball or its clubs.