Keith Hernandez is one and done as a Fox postseason baseball analyst, The Post has learned.

While the network announced Monday a new contract for David Ortiz on its major pre- and postgame presentations, Hernandez will not be brought back. When reached by phone, Hernandez confirmed to The Post he had been told of Fox’s decision earlier Monday.

“It is disappointing, but it was a good experience,” Hernandez said.

Hernandez, 64, remains gainfully employed with his work for SNY as part of Mets telecasts. He also has been publicizing his book, “I’m Keith Hernandez,” with his new Twitter account, which has received acclaim, as has his heavily featured cat. The book, Hernandez said, is in its fifth printing.

Hernandez was brought in by Fox last year to replace Pete Rose. Rose was let go after reports he allegedly had a sexual relationship with an underage girl in the 1970s.

On a set with Ortiz, Alex Rodriguez and Frank Thomas, Hernandez often didn’t get to show the full extent of his personality. It appears Hernandez is either going to be replaced by a current player from a team that fails to qualify for the playoffs or not at all, a source said.

Ortiz signed a multi-year contract, Fox announced Monday. He and Rodriguez have made up after Ortiz gave Rodriguez the silent treatment following one of A-Rod’s lawyers, during the Biogenesis case, implying that Big Papi used steroids but wasn’t being investigated like Rodriguez. Rodriguez eventually was banned for one year. A-Rod and Big Papi got along during last year’s productions.