Moyer said he did not feel anything tweak or pop.
"I just couldn't finish pitches," he said.
Moyer said he expects to return to Philadelphia for testing.
"My goal is to keep a positive mental outlook, whatever the diagnosis is," he said. "I expect to pitch again."
Todd Zolecki is a reporter for MLB.com.
This story was not subject to the approval of Major League Baseball or its clubs.