Again, it wasn't designed for Rosen to beat out Fitz, Remember they chose Fitz first possibly guaranteeing him the starting position knowing that he knew the offense, and plus giving Flores something that he can hang his hat on, If the dolphins were tanking for Tua they would have kept Rosen in the game and let him take some more lumps, at some point Flores gave himself the only chance to save face with Fitz was to re insert him knowing Rosen time wasn't going to be the dolphins QB any way in 2019.