Boxer Amir Khan says he was so serious about fighting Floyd Mayweather -- he offered to take the fight for FREE ... but Mayweather still ducked him because he's "afraid."
Khan was a in Pebble Beach for the Pro Am -- when he dished about the failed negotiations to fight the legend ... and talked some smack at the same time.
We also asked how he felt about the fact his next opponent Canelo Alvarez is already in talks to fight Gennady Golovkin later this year. Khan says Canelo is making a HUGE mistake.