Not as Rachel, though. The role of Monica was written specifically for Janeane. Courtney Cox was offered the role of Rachel and turned it down, said she wanted Monica instead. So the part of Rachel was offered to Jennifer Aniston. Courtney still almost wasn't Monica, it was a close call between her and The Facts of Life veteran Nancy McKeon. Janeane went on to have the worst experience of her life on Saturday Night Live, lasting less than one season there.

https://www.tvline.com/2070346/monica-friends-initially-written-snl-star-janeane-garofalo/