Sandy Alderson said team doctors did not locate the spur until last month, after Francisco resumed throwing in preparation for 2013 and still had discomfort. According to the GM, Francisco’s spur was obstructed from view during his September exam by whatever else was going on in the elbow.

“I think the spur was discovered and finally diagnosed just before he had the surgery,” Alderson said. “It was a matter of conservative treatment, but there really were a couple of issues related to the elbow, and the primary issue was obscuring the spur issue.”
http://espn.go.com/blog/new-york/met...ncisco-surgery