The three-time All-Star right-hander felt discomfort after a 27-pitch bullpen session last week and saw a specialist on Monday. Strasburg, who is 1-2 with a 4.57 ERA in five starts this season, was diagnosed with neurogenic thoracic outlet syndrome and will be operated on by Dr. Greg Pearl in Dallas on Wednesday.
"He's down, he's frustrated,'' manager Dave Martinez said Tuesday. "Hopefully after this procedure is done, it's the next hurdle, recovering and then starting to rehab as soon as he possibly can.''
Injuries have limited Strasburg to seven starts since he was named MVP of Washington's World Series win over Houston two years ago. He last pitched on June 1.
Martinez said he expects Strasburg to be ready for the start of spring training next year.
"I know what kind of workhorse he is when healthy,'' Martinez said.