Rapper Joell Ortiz -- BRING JOHNNY MANZIEL TO THE JETS

Rapper Joell Ortiz -- 1/4th of the supergroup Slaughterhouse -- says he has a plan to SAVE the NY Jets ... and it centers around Johnny Manziel.

The Brooklyn rapper -- who signed with Eminem's Shady Records -- was out in NYC last night and had a message for Jets Nation ... DON'T GIVE UP HOPE!!

Take a listen to Joell's plan ... it could be his audition to be the next NY Jets G.M.