Benitez has remained coy on whether he will extend his stay at the San Paolo, where his contract will expire at the end of this season.
But Napoli's 1-0 defeat to Lazio (2-1 on aggregate) in the deciding second leg of the Cup semi-final on Wednesday appears to have hastened Benitez's eventual departure.
Sampdoria coach Sinisa Mihajlovic, who has steered the Genoese side to fifth place in Serie A and in contention for a Europa League place, has been linked to Benitez's post although there is also reported interest from AC Milan.
Luciano Spalletti, former coach of Roma who won four trophies including two Russian league titles in his last spell, with Zenit Saint Petersburg, is also in the frame according to reports.
Napoli had been pressing for a second place finish for most of this season but a six-game winless run in the league has seen Benitez's side drop to sixth place, a point behind Sampdoria and eight adrift of Lazio in the third and last Champions League place with nine games remaining.
Napoli remain in contention in the Europa League - they face Wolfsburg in the quarter-final on April 16th and 23rd - but their Cup elimination has merely added to their league woes.
Napoli president Aurelio De Laurentiis made no mention of Benitez's fate but was furious following their Cup elimination.
"These players seem to be far too distracted. I've invested €386 million in the squad in recent years, I have a right to see some kind of return," De Laurentiis told Sportitalia.
"From now until the end of the season, if we don't change tack and the players are not capable of playing for the jersey, they are going into a training retreat.
"I hope this will prove a turning point and help us find some pride. Our performances of late have not been worthy of Napoli." Napoli host Fiorentina on Sunday.