Ten minutes after injured Yankee Alex Rodriguez walked into Equinox South Beach yesterday, an "extremely bubbly and friendly" Cameron Diaz showed up in black leggings, tank top and, noted our spy, "no makeup." Diaz hopped on the Stairmaster next to her man, smiling at him before putting on her iPod and "getting serious about her workout." After about an hour, Diaz hopped off, said goodbye and left A-Rod to his "intense stretch." No stretch, however, is as intense as our failed attempt to make this sighting more interesting. Stars, they're just like us. Yawn.