Drs. Michael Mitchell (George Clooney) and Jeffrey Rosen (Noah Wyle): Two doctors whom Rachel and Monica meet at a hospital, then go on a date with, with Monica and Rachel pretending to be each other for health insurance purposes—eventually causing things to go wild. Dr. Mitchell later saves the life of Ross's monkey, Marcel, who swallows alphabet tiles from a "Scrabble" game that nearly choke him to death. (Clooney and Wyle were also cast as physicians on the NBC medical drama 'ER' when they appeared together on Friends.)