With Polizzi pregnant and Sorrentino seeking substance-abuse treatment, the network could be worried it will lose its sex-crazed, alcohol-fueled edge, the entertainment Web site reported Saturday.
MTV released a statement this week saying it plans to return the entire cast for Season 6, but a source close to 495 Productions told TMZ they are looking for fresh faces.
The production company plans to focus more on new cast members but still keep the familiar faces around to keep fans hooked, the source said.
Season 6 of "Jersey Shore" begins production this summer.
Notable deaths of 2014 [PHOTOS]