The People's Elbow apparently now needs an MRI ... 'cause Dwayne Johnson just revealed his famed body part suffered an injury on the set of his new movie this week -- and the wound looks gnarly.
The Rock said on his Instagram page Tuesday that he hurt the wing while filming some scenes for "The Smashing Machine" -- an upcoming flick all about the life of MMA legend Mark Kerr.
Dwayne didn't exactly clarify how he sustained the ailment ... although he joked, "Anytime your film is called 'The Smashing Machine,' well, you're kind of going to get smashed up."
Check out the video he posted to IG ... the damage to his elbow was visible -- as he had a large sack of fluid hanging off of it.
"It looks like I have a cantaloupe in the bottom of my elbow," the WWE Superstar quipped.
The good news ... Dwayne told his followers the pain is manageable at the moment -- although he will need to get some testing done once the inflammation goes down in order to determine the extent of the injury.
In the meantime, Johnson made it clear he's going to tough it out -- perhaps with a lot of help from his tequila brand along the way.