MLB's Josh Naylor Gruesomely Breaks Leg In Violent Collision W/ Teammate

Cleveland Indians outfielder Josh Naylor broke his leg in a horrifying fashion after colliding with his teammate during a game Sunday ... and video of the play is VERY hard to watch.

The gruesome scene all went down in the 4th inning of the Tribe's game against the Minnesota Twins ... when Naylor was trying to track down a fly ball in right field.

The problem ... his teammate, Ernie Clement, was charging for the ball as well -- and when the baseball finally came down from the sky, the two crashed into each other HARD.

The collision sent Naylor flying -- and when he landed, his leg bent awkwardly underneath him ... horrifically twisting it.

You can see in slow-motion replay, Naylor was in EXTREME pain ... writhing on the ground.

Naylor was eventually carted off the field and taken to the hospital ... and after the game, Indians manager Terry Francona confirmed his player was dealing with a significant injury.

"We know that there's a fracture," Francona told reporters. "Other than that, he's being evaluated over at the hospital right now."

Naylor had played in 69 games for Cleveland this season ... hitting 7 home runs and batting .253.