VIERA, Fla. -- Nationals left-hander Sammy Solis will need Tommy John surgery, according to general manager Mike Rizzo.

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.

Burnett reflects on mixed results from 2011

VIERA, Fla. -- Before the All-Star break in 2011, Nationals reliever Sean Burnett was having a season to forget, going 3-5 with a 5.40 ERA. After the break, Burnett was back to being the pitcher who was arguably the team's MVP in 2010. He had a 1.80 ERA in 28 games.

What was the difference in the two halves? After a talk with former teammates Livan Hernandez and Matt Stairs in Houston last July, Burnett decided to stand on the first-base side of the rubber instead of the third-base side.

During a bullpen session in Houston, Hernandez watched Burnett, while Stairs stood in an imaginary batter's box to help Burnett. It proved to be the turning point of Burnett's season.

"I moved back to where I naturally felt comfortable for most of my life," Burnett said. "I obviously felt great all year. There was no excuse on that part. I struggled in the first half and I had no real answer for that. Veteran guys like 'Livo' and Matt Stairs told me to keep going out there. Things would eventually turn your way. Once I started going to the first-base side of the rubber, things started going my way."

Burnett is expected to be the lefty specialist out of the bullpen this season.

Werth sits out practice with back spasms

VIERA, Fla. -- Nationals outfielder Jayson Werth did not work out Tuesday because of lower back spasms. The injury is not considered serious.

It's not known if he will miss games to start the Grapefruit League season, which begins Saturday against the Astros.

"It's something I'm not going to take any chances with," manager Davey Johnson said. "I know he worked out a lot in D.C., so I'm not worried about him."

Right-hander Yunesky Maya also didn't work out on Tuesday because he was sick, according to Johnson. Maya is expected to be back on the mound soon.