The only Rachel Green we knew was Jennifer Anniston, so it is hard to think of anyone else playing that character.
Tiffani Thiessen (who played the character of Kelly Kapowski in Saved By The Bell) was chatting to Sirius XM's You Up With Nikki Glazer recently, and revealed that she auditioned for the part of Rachel Green.
"I was a little too young"
She said "I was a little too young to the pairing of the rest of them." She would've been 20 at the time Friends started, & Jennifer was 25 and the youngest member of the cast of the show. Tiffani isn't the only Saved by the Bell alumni who went for the part of Rachel. Elizabeth Berkley, who played Jessie Spano, also auditioned, but didn't get the role either.
Courteney Cox who went onto play Monica in Friends, almost played the role of Rachel, but said that she felt she was better suited to playing Monica Geller.
Saved By The Bell ran for five seasons from 1989 to 1993. Friends became one of the most popular television shows of all time. It ran for 10 seasons from 1994 to 2004, but of course it is loved so much that it's still repeated to this day.