Zabaleta believes Mancini's instilled resilience will tilt the balance in their Carling Cup semi against Manchester United United.
Zabaleta said: "This match is important in the club's history. We need to create history and this could be the start of it.
"We needed to work on our defence and tactical play and, like all Italian coaches, Roberto Mancini has done it.
"We conceded nine goals in Mark Hughes's last three matches and that is too many. Now we are more solid.
"Mark was a fantastic boss, but that's history. Everyone now believes in Mancini."