Nationals rookie sensation Stephen Strasburg underwent season-ending Tommy John surgery on Friday.
"He had his surgery," Nationals general manager Mike Rizzo said. "It was performed by Dr. Lew Yocum and Dr. Wiemi Douoguih. I got a call from both and they said it was successful surgery, he came through it with flying colors. It went smooth and uneventful. He will spend the night in the hospital tonight and go back home to San Diego on Saturday and begin his rehab."
In 12 games for the Nats, the heralded right-hander was 5-3 with a 2.91 ERA and 92 strikeouts.
Strasburg, the first overall pick in the 2009 First-Year Player Draft, is expected to be out between 12 and 18 months.
The Nats are hopeful that he can begin light throwing in four months, but they understand it likely will be a long road for him to return to the form that made him the talk of baseball earlier in the season.