BIG BEAR LAKE, Calif. (AP) When Saul Alvarez steps from a black SUV into a swath of media and fans, he keeps his head low and his gaze neutral as he calmly follows his entourage to work. Footwork, timing, focus they're all impeccable.

At just 23 years old, the freckle-faced Mexican fighter called Canelo has mastered the moves of a star. He usually handles his skyrocketing celebrity with calm and poise, always coming off as a hungry, serious athlete who cares little for his sport's near-requisite bragging and boasting.

Just three years after the Mexican junior middleweight champion's first major U.S. fights, Alvarez will be under his sport's biggest spotlight Saturday night in Las Vegas when he faces Floyd Mayweather Jr., the biggest star of them all.