Antonio Conte's side lead the division by nine points with seven games to go and Mazzarri now feels that overhauling the champions is looking improbable.
"Of course it is very unlikely that we can finish on top, but in football everything can happen, so you never know," Mazzarri told reporters ahead of their clash with AC Milan today.
"No, there is no regret for not being closer to Juventus in the table, there are still seven games to go. Once again I am pointing out that we have been enjoying a great season. Looking at our numbers - we have got 14 points more than last season."
The Naples outfit travel to the San Siro for today's clash four points ahead of Milan, who sit third in the division.