Solis will have surgery on the elbow next Tuesday. The procedure will be performed by Dr. Lewis Yocum, the same person who surgically repaired the elbows of Jordan Zimmermann and Stephen Strasburg. Solis is expected to be ready for Spring Training in 2013.
Solis, who ranked 86th overall on MLB.com's Prospect Watch and fourth among the Nationals' prospects, made a combined 17 appearances for Class A Hagerstown and Potomac last season and went a combined 8-3 with a 3.26 ERA. He had 93 strikeouts in 96 2/3 innings.
"He is a terrific prospect," Rizzo said. "He has great stuff. We always thought -- even after we drafted him -- he was quick to the big leagues. This [the surgery] will derail that a little bit."
This past offseason, Solis had what appeared to be a minor elbow injury while playing in the Arizona Fall League and was expected to be 100 percent by Spring Training. When he arrived in camp, Solis appeared healthy, playing catch and having bullpen sessions.
"He passed all of the tests ... as far as the physical part of it," Rizzo said. "Because he passed all of the physical tests that they put him through, they felt the most prudent course of action would be to have him rest for a month then ramp him back up into a throwing program to see if we could avoid the Tommy John surgery."
It was on Friday that Solis experienced elbow problems and was sent to see the team's medical director, Dr. Wiemi Douoguih, who recommended Tommy John surgery. Solis then went to Southern California on Tuesday to see Dr. Yocum, who confirmed that Solis needed surgery.
This is the second major injury for Solis in the past four years. In 2009, Solis missed nearly all of the season with a herniated disk in his back, an injury he suffered while lifting weights two years earlier. The setback limited the 6-foot-5 lefty to two games while attending the University of San Diego.