A Tampa Bay Rays prospect was hit so hard in the head by a line drive Thursday, he began convulsing on the mound ... and the scene was absolutely horrifying.
Tyler Zombro was pitching for the Rays' Triple-A affiliate, the Durham Bulls, when the tragedy struck ... and the Bulls say the 26-year-old has since been hospitalized.
The team added he's currently in "stable" condition.
The play was as scary as any as you'll see on a baseball diamond ... in the 8th inning of the Bulls' tilt with the Norfolk Tides, Zombro was hit flush in the head by a comebacker.