The 45-year-old – who starred alongside Diaz in The Sweetest Thing – told reporters that Diaz is keen to spend more time with her husband Benji Madden.
She has since retracted her claim, telling her Twitter followers that she was simply “making a joke”.
She posted: “BREAKING NEWS. Guys please, I was making a joke in an interview. CAMERON DIAZ is NOT retiring from ANYTHING. And for more breaking news: I am NOW retiring from being Cameron Diaz’s spokesperson.”