Canelo Alvarez says he wouldn't be caught dead in an MMA cage 'cause he's got too much love and respect for boxing ... unlike Floyd Mayweather.
With all the buzz about Floyd possibly taking a UFC fight, we had to ask Canelo if he'd consider crossing over, too.
Canelo shut that down quick -- and shaded his former rival in the process.
"I respect boxing. Boxing's my sport. That's what I love. The other sport, that's something we'll never know," he told TMZ Sports.
As for Floyd -- "With him you never know ... but you know what? Whatever he does doesn't interest me."
Of course, Canelo's focus is on his May 5 rematch vs. GGG ... and both guys let us know why this one's a way bigger deal than their first matchup.