The Azzurri have fallen six points behind league leaders Juventus after a run of consecutive defeats, but the Swiss is confident that his team can reverse their fortunes.
"It's still early in the season," he told Radio Kiss Kiss Napoli.
"We shouldn't think that we are already out of the running, we have a lot of games against our rivals to play at the Stadio San Paolo where we have an extra gear.
"We are not going through a good spell of results. We have lost our last three games and that is rare for a club like ours. But we want to return to winning ways.
Napoli are next in action on Monday night when they visit Lazio.