General manager Mike Rizzo said Friday that an enhanced MRI taken a day earlier revealed the extent of the injury to the right elbow.
The 22-year-old right-hander will travel to the West Coast for a second opinion. But Rizzo says he anticipates Strasburg will require surgery, ruling him out for 12 to 18 months.
The news brings an abrupt halt to Strasburg's promising first season. He struck out 14 batters in his major league debut in June. Strasburg is 5-3 with a 2.91 ERA and 92 strikeouts in 68 innings..