The Azzurri have lost two of their first four Serie A matches and were knocked out of the Champions League at the playoff stage.
"Napoli will rise again. [Rafael] Benitez speaks the truth when he mentioned a united group that's working a lot in this moment," Maggio told Radio Kiss Kiss Napoli. "We know our strengths and we know that this group, after doing so well only a few months ago, will return to its best form.
"We will find the right serenity to get out of this situation because the squad is strong, we have experience. The expectations were different, but there's time to return to the top.
"We have very strong players in this team, the same as last year. It's a period that's a bit so so, we didn't start well and we have understood the errors we have committed and we are trying to resolve them."
Napoli are currently 10th in the Serie A table.