Ziegler's operation more complicated than expected

Anticipated arthroscopic procedure becomes microfracture surgery

Ziegler's operation more complicated than expected

SAN FRANCISCO -- D-backs reliever Brad Ziegler underwent microfracture surgery on his left knee Tuesday, a more serious procedure than initially anticipated.

The procedure is known as microfracture surgery because tiny fractures are made in the underlying bone of the knee to help new cartilage to develop.

The initial hope was that the fraying of the cartilage could be taken care of through arthroscopic surgery, but once surgeons started, they realized more needed to be done.

While the recovery will be longer than expected, both manager Kirk Gibson and acting general manager Kevin Towers said they expect Ziegler will be ready when Spring Training starts next year.

Steve Gilbert is a reporter for MLB.com. Read his blog, Inside the D-backs, and follow him on Twitter @SteveGilbertMLB. This story was not subject to the approval of Major League Baseball or its clubs.