Before he became associated with his fan-favorite Gilmore Girls character Jess Mariano, Milo Ventimiglia appeared in one episode of the Saved By The Bell spin-off, The New Class. Although only two original characters were part of this series, including Screech Powers (Dustin Diamond) and Richard Belding (Dennis Hawkins), a few now-famous stars had small roles, including Gabrielle Union and James Marsden. These characters may not have been as fleshed out as the main cast, but they still held significance for the show's relatable high school plotlines.

https://screenrant.com/milo-ventimiglia-saved-by-the-bell-greg-character-explained/