Walter Mazzarri will leave Edinson Cavani out of his starting line up to face Villarreal this evening, according to La Gazzetta dello Sport.
It would appear that Napoli's priorities lie with Serie A rather than the Europa League, although there is a real possibility that he will come off the bench.
Napoli are due to play Milan at San Siro on Monday night in what is already being billed as a title decider by the Italian media.
Mazzarri's side currently lie second in the table, just three points behind the League leaders with 12 games remaining.
Ezequiel Lavezzi is expected to spearhead Napoli's attack for the second leg at El Madrigal. It's thought Mazzarri took this decision because he is suspended for the trip to Milan.