Celebrities who had cameos on 'Seinfeld'
Keith Hernandez
Hernandez is not an actor by trade. No, he made his name playing at an All-Star level for the New York Mets. So naturally he got to play himself in “Seinfeld.” While that seemed to stretch his acting chops, it was still an enjoyable couple of episodes featuring Hernandez, who befriended Jerry and dated Elaine.