كتب : Omar AbdelAziz
The Whites missed out on a CAF Champions League spot after two straight defeats to Telecom Egypt (3-2) and Petrojet (3-1), whereas ENPPI are unbeaten in seven games.
"The recent defeats could be positive to us in one way, I think it was a useful lesson," Zaki told FilGoal.com.
"We have been doing well in the league since a while, and we needed that shake in order not get carried away.
"The defeats increased our concentration and made us more cautious."
The former ENPPI striker believes that a win over his former club on Sunday is the best way to recompense losing second place in the league.
"We are sorry for our fans because we let them down in the league, but we promise to win the cup for them," added Zaki.
The Egypt ace is yet to win any silverware with Zamalek since joining in 2006, as his exit seems to be imminent this summer.