Berti says critics are demanding too much from Mazzarri with Inter currently in "transition".
He explained: "Sacking? I would go ahead with Mazzarri, I can't see any alternatives to the Tuscan coach at this time when the club is still in transition.
"Walter Zenga? He could offer more excitement to the team, but yesterday, however, the fans supported the team until the end.
"I think it is necessary to make investments in January at least better than what has been made, which is very disappointing."
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