That's a big relief for the A's, who stated in a release that Parker is resting comfortably. His recovery time is not yet known.
"What we heard, that the ligament is still intact, that's a much better result than looking at another Tommy John," said A's manager Bob Melvin. "He sent me a text, and he seems to be in pretty good spirits about it.
"We'll obviously take it pretty easy with him, but [recovery time] is not obviously what a typical Tommy John would be."
Parker originally suffered the fracture, repaired by Dr. James Andrews, while making a rehab start with Triple-A Nashville on May 8. Before the incident, the right-hander was expected back in the A's rotation by month's end, after missing all of 2014 following his second Tommy John surgery.
Parker, 26, went 25-16 with a 3.73 ERA in his prior two seasons with Oakland.
Jane Lee is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.