On Tuesday, doctors removed a cavernous malformation — a cluster of blood vessels that had been growing on Westmoreland's brain stem.
Westmoreland left camp March 4 after reportedly experiencing headaches and numbness associated with this rare condition, which could have led to seizures and brain hemorrhaging if untreated.
The surgery, performed at the Barrow Neurological Institute in Phoenix, Ariz., reportedly took five hours, and Westmoreland remains in intensive care.
A statement from the Red Sox, attributed to general manager Theo Epstein said: "Due to the complexity of this surgery, Ryan will face a difficult period initially before beginning his recovery."
Reporters in Florida, where the Red Sox train, got a reaction from manager Terry Francona about the surgery itself — which was deemed a success.
"It sounds like very encouraging news," Sox manager Terry Francona said. "We're obviously thrilled about that. We're thankful."
Just 19 years old, Westmoreland grew up in Rhode Island as a Red Sox fan and seemed on course for living the impossible dream of playing someday for his favorite team.
Baseball America rates Westmoreland, an outfielder, as the top prospect in the Red Sox system and one of the top 20 or so in the majors. His skills have been likened to those of Grady Sizemore(notes) of the Cleveland Indians.
Because of the delicate nature of the surgery, Westmoreland is offered no guarantees about neurological damage as it relates to vision and movement, writes former Y! Sports' baseball reporter Gordon Edes, now at ESPN Boston.
Not only is Westmoreland's baseball career in jeopardy, but a return to a so-called normal life is not assured.