Polo Player Choppered to Hospital After Major Injury During Match

Terrifying moment at a major polo tournament in Argentina -- when a player fell off his horse and was hurt so badly, he needed to be airlifted to a nearby hospital for emergency treatment.

The player is Federico Rooney -- who was playing for team Marcos Juarez in the famous Flag Open on Sunday when disaster struck.

Both Rooney and his horse crashed to the ground -- and Rooney didn't get up.

Medical personnel raced onto the field to treat Rooney -- and ultimately loaded him onto a helicopter to be transported to a nearby hospital.

Local reports say Rooney suffered a skull fracture and blood clots -- and he was placed into a medically induced coma.

Despite the horrible injuries, he's reportedly stable and expected to recover.

Still, the injury left a black cloud over the tournament -- and the remaining teams decided to call the rest of the event off in light of Rooney's injuries.

We know what you're thinking ... we've been trying to find out if the horse is okay too -- but so far, it's unclear.

Attempts to reach event organizers have been unsuccessful so far.