Juve and Inter face off on Sunday in a game that could decide the Scudetto this season.
Former Inter boss Mancini said, "I don't think Maurizio Sarri is in great difficulty, he is still leading in the league, and he can bring Juve into the quarter final of the Champions League, even if they lost to Lyon.
“They are still also in the Italian Cup. After many years of success, Juve may have problems, but it doesn't depend on Sarri, otherwise the same team would always win, everywhere."
He added: “Serie A is still open and there are three teams in the running. It will be a good sprint to the end."