"He'll get a cleanup on his shoulder," Ryan said. "It's not a serious surgery, but it's something we think needs to be done."
Ryan said Deduno will need to rehab his shoulder over the next few months, but will be ready for Spring Training next year. Deduno won't pitch in winter ball this offseason.
The 30-year-old right-hander finishes the 2013 season at 8-8 with a 3.83 ERA in 18 starts with 67 strikeouts and 41 walks in 108 innings. He was originally placed on the 15-day disabled list on Aug. 30, before being transferred to the 60-day disabled list on Monday.
Rhett Bollinger is a reporter for MLB.com. Read his blog, Bollinger Beat, and follow him on Twitter @RhettBollinger. This story was not subject to the approval of Major League Baseball or its clubs.