Vasquez was working on drills on one of the the practice fields at Boston's JetBlue Park complex Thursday when pitcher Hirokazu Sawamura fired a ball his way ... mistakenly thinking Vasquez was looking in his direction.
We know what you're thinking ... and no, video of the incident has not been released.
The ball struck 30-year-old Vasquez with such force, it opened up a nasty gash under his left eye -- requiring immediate medical attention.
Vasquez required several stitches to close the wound -- and says if it wasn't for the sunglasses, doctors believe he might have lost his left eyeball.