'Jersey Shore' -- Producers Looking to Phase Out The Situation & Snooki

With Snooki pregnant and The Situation getting sober, the people behind "Jersey Shore" are FREAKED the show will lose its sex-crazed alcohol-fueled edge -- so they're looking to phase the two out ... in favor of newer, wilder castmates.

MTV released a statement earlier this week -- following news Sitch was seeking substance abuse treatment -- claiming the network expects the entire cast to return for Season 6 ... but sources close to 495 Productions tell TMZ, the production company is currently looking for new talent.

According to sources, 495 desperately wants to keep things fresh -- and folding in new castmates will help transition the show into a new generation ... while still keeping old fans hooked.

We're told 495 plans to limit Snooki and The Situation's roles on the new season -- giving new cast members more screen time instead.