Nats P Zimmermann out 12-18 months

ATLANTA -- Jordan Zimmermann will have reconstructive elbow surgery next week, leaving the Washington Nationals without their top pitching prospect for at least a year.

Manager Jim Riggleman said the normal recovery period is 12 to 18 months, a timetable that could keep the 23-year-old Zimmermann out until the 2011 season.

Acting general manager Mike Rizzo said Zimmermann is "as upbeat as you can be" about the surgery, which will be performed on his right elbow by Tommy John expert Dr. Lewis Yocum next Wednesday in California.

Rizzo announced plans for the surgery after Yocum reviewed Zimmermann's MRI exam.

"He confirms what the other two doctors have said," Rizzo said Wednesday.

Earlier this week, Dr. James Andrews reviewed the MRI exam and agreed with a Nationals team doctor that surgery was necessary to repair a torn ligament.

Rizzo said the loss of Zimmermann is only a temporary setback to a promising career.

"We foresee a long, successful career for him," Rizzo said.

Zimmermann was 3-5 with a 4.63 ERA in 16 starts for Washington in his first season above Double-A. He was considered a cornerstone of the team's long-term rotation.

"He understands what's going on," Rizzo said. "He's keeping his spirits up."

Riggleman said Zimmermann "was very upset" earlier in the week.

"We just encouraged him that this is something that it seems like so many pitchers go through now, whether it's your elbow or your shoulder," Riggleman said Tuesday.

"The upside is that the doctors have perfected these operations to the point where quite a few guys -- most guys -- come back as good and sometimes better than ever. He's young and we feel like that will be the path he takes."

Rizzo said Zimmermann will fly to California on Tuesday and may leave as early as Thursday.

Zimmermann went on the disabled list July 22 with a sore elbow. He made a rehabilitation start at Class-A Potomac on Aug. 4. The right-hander felt more discomfort in the elbow, forcing him to scrap plans for another rehab appearance.