Top pick Giolito to undergo Tommy John surgery

PHILADELPHIA -- Nationals general manager Mike Rizzo said the impending Tommy John surgery for top pick Lucas Giolito did not necessarily come as a surprise, and that the club remains confident in the 18-year-old right-hander's promise after he rehabilitates.

Giolito appeared in just one game for the Gulf Coast League Nationals, tossing two innings -- allowing one run and two hits while striking out one -- before feeling some pain.

"After we drafted him, we were well aware of the possibilities of the elbow injury and we tried to test the waters and have him throw in Instructional League rehab and let it loose and see where we were at," Rizzo said. "He did it and he felt some pain, so we had him checked out by our doctor. They saw that he had a complete tear of the ulnar collateral ligament. We got a second opinion from [Dr. Lewis Yocum] and he seconded the diagnosis of our team doctor and he scheduled him to have the surgery at the end of August."

Rizzo believes Giolito -- the Nats' first-round pick in the 2012 First-Year Player Draft out of Harvard-Westlake High School in Los Angeles -- was comforted by the Nationals' history of successfully rehabbing pitchers from Tommy John surgery, including Stephen Strasburg and Jordan Zimmermann.

"I think he feels relieved that he's with the Washington Nationals," Rizzo said. "I think he'd be at UCLA if we weren't the team that drafted him. He knows that we care about our players, he knows that we're going to get this fixed and rehab him and he feels very confident he's going to bounce back and pitch in Washington real soon."