Maurizio Sarri told each of his Napoli players they are a "d*******" if they watch Serie A leaders Juventus' matches in the closing stages of the season.
Juve faced Sassuolo on Friday and opened up a six-point lead over Napoli at the summit with an 18th triumph in 19 Serie A outings with a 1-0 victory.
Sarri admitted his frustration over the staggered fixture list ahead of his team's trip to Palermo on Sunday, but has emphasised to his players the importance of only focusing on themselves in the race for the Scudetto.
"We have to think about each game without casting an eye at others. I said to the guys on Friday: whoever watches Juve is a d*******," said the coach.
"We need to only think about the match tomorrow. I don't like the fact the matches are spread out over several days.
"If we look at those ahead of us we risk anxiety, because we can't do anything about a team that has won non-stop for five months. We can't look over our shoulders, as otherwise we'll get scared.
"Playing after Juve or before won't add pressure, because we have to always assume they'll win. Juve have a history and a winning mentality that can only be earned after winning everything for four years and reaching the Champions League Final.
"We are up against an exceptional Juve side who have won 18 of the last 19 games. We have a dream and tomorrow we must use that dream to parry Palermo's motivation."