Whether it's Jerry taping the Mets game during the pilot, or the Mets hat in Jerry's apartment, there is no shortage of Mets cameos. However, the most iconic moment of the Mets on Seinfeld is when Keith Hernandez guest-starred in the two-part episode "The Boyfriend" during season 3. With Keith Hernandez in the house, major props to @tigers media relations for Seinfeld-themed bullet points of Keith’s episode. During that scene, Elaine thinks to herself, "Who does this guy think he is, and Keith thinks to himself, "I'm Keith Hernandez." To make that section better, it references a Mets first baseman, only it's Pete Alonso and not Hernandez.