Italy currently lead Group B but Maggio insists that complacency must not become an issue on Friday evening.
The Napoli defender said: "We still don't know too much about Armenia, but we will as there is still plenty of time before the match.
"A few days ago I spoke to my Napoli teammate Marek Hamsik who faced them last year. He told me that they don't have great individual qualities, but they are a side who work very hard."
Armenia have beaten Malta and lost to Bulgaria in the group so far.