Zigic scored the winning goal in the Carling quarter-final clash with rivals Aston Villa earlier this week.
But the Serbian striker has had a poor start for Birmingham since joining the club in a £6million deal from Valencia over the summer.
“Listen, Ziggy is 29, he is an experienced player, he is a Serbian so he is a proud man,” said McLeish.
“He has come over to the Premier League and he wants to make an impression.
“He has tried to adjust to the English game.
“He is used to playing the European game where there is a build-up and there are probably only four or five headers in an entire game.
“In England it’s crash, bang, wallop and he has got to compete for everything.
“It’s been a bit of a culture shock to him. I was ready to take him off when he scored.
“It was great that he scored and hopefully he wins a few friends with that goal.”