NHL's Aaron Ekblad Suffers Gruesome Knee Injury, Leaves Ice On Stretcher

Horrific scene on the NHL ice Sunday ... a star player for the Florida Panthers suffered a gruesome knee injury mid-game and was forced to leave the match on a stretcher.

Aaron Ekblad -- who was leading the Panthers in total ice time this season -- took a check from an opponent in Florida's game against the Dallas Stars when things went terrifyingly wrong.

Ekblad's knee and skate got caught under his body ... and when he came crashing down on top of the leg -- it all bent and crumpled awkwardly.

***WARNING: THE CLIP IS TOUGH TO WATCH***

You can see in video immediately after the injury ... Ekblad was in SERIOUS pain -- writhing on the ice, screaming, and holding on tightly to team trainers.

The defenseman was eventually strapped to a stretcher and taken off the ice. In a postgame update, Panthers head coach Joel Quenneville said Ekblad would be out indefinitely.

"It was pretty tough," Ekblad's teammate, Jonathan Huberdeau, told reporters after the game ... before adding, "You hear him scream too. I mean, it must have hurt so bad."