Sacchi was reacting to the criticism aimed at Inzaghi for Inter's Coppa Italia semifinal defeat to AC Milan. The Rossonero thumped Inter 3-0 to wreck the Nerazzurri's Treble hopes.
Sacchi told La Gazzetta dello Sport: "Luckily there are still wise directors, with their heads screwed on. I ask myself, after what we've seen in recent seasons: how can we discuss Simone Inzaghi?
"The world of football, at times, is incomprehensible. Well, if in Madrid they criticise (Carlo) Ancelotti, now anything goes...
"Let's rewind the tape: after the victory in Munich against Bayern he was a phenomenon and 15 days later, more or less, he became a donkey?
"Putting a coach in the dock because he lost a couple of games is not part of my way of thinking. Then there may also be mistakes that have been made, of course. But I ask those who are complaining now: have you ever made a mistake or are you perfect? Errare humanum est, and it seems to me that no one can consider themselves immune."
"Inzaghi had to do it"
Inzaghi was also attacked for the team selection used against Milan, with an eye on the Champions League semifinal against Barcelona next week.
Sacchi added: "If he did it, it means he needed it. I don't know a coach who shoots himself in the foot. Sure, maybe Inter's second lines aren't at the same level as the starters. But I don't know any team, around Europe, where the quality of the reserves is similar to that of the starters.
"Not even Real Madrid... It's logical that (Davide) Frattesi isn't (Nico) Barella, that (Kristjan) Asllani doesn't have (Hakan) Calhanoglu's class or that (Mehdi) Taremi doesn't have an impact like (Marcus) Thuram. When you play so many games as Inter have done this season, you have to take these risks."