Billy Joe was loaded into an ambulance and taken to a nearby hospital for evaluation where he was diagnosed with a quadripod fracture, according to The Athletic's Mike Coppinger.
FYI, the injury essentially means Saunders' orbital bone was smashed so badly, his cheekbone area caved in.
BJ's promoter, Eddie Hearn, announced he would undergo surgery on Sunday -- though unclear how it went at this point.
Hearn told Coppinger the recovery will take several months -- and it doesn't seem like it's a certainty Saunders will ever be able to fight again.
The long story short, the integrity of BJ's cheekbone area has been structurally compromised since it was broken in 4 spots ... and for a guy who gets punched in the face for a living, that's a VERY bad thing.
Dr. David Abbasi -- an orthopedic surgeon who sometimes works combat sports events -- broke down the injury and it's scary stuff.
Saunders was 30-0 before the Canelo fight -- and looked pretty good in the moments before the fight ended.
He was sticking and moving and landing real shots ... but in the end, Canelo's power proved too much.
Here's hoping Saunders can make a complete recovery and get back to doing what he loves.