The president is furious at the form being shown by Rafa Benitez's side and has issued them an ultimatum if they cannot prove themselves

Napoli president Aurelio De Laurentiis has slammed his players' "squalid" performances and threatened to cancel their holidays unless they find form.

Defending champions Napoli suffered a 1-0 home defeat to Lazio on Wednesday in the Coppa Italia, with Senad Lulic's 79th-minute goal eliminating them 2-1 on aggregate at the semi-final stage.

Rafa Benitez refrained from tearing into his players after the game but De Laurentiis had no such issue as he criticised the Stadio San Paolo stars, saying he'll drag them to a training camp at the end of 2014-15 if they don't arrest form which has seen them win just one of their last nine matches.

"We have a commitment to the fans, who are quite right to be unhappy," De Laurentiis told SportItalia.

"From today until the end of the season - if we don't change course and the players are incapable of honouring the jersey on their back - then they are going into a training retreat for an undetermined length of time.

"I hope all of this will serve as a turning point to spark some pride. We have put in some squalid performances that are unworthy of Napoli.

"From today, we change. We need a training session on mentality, and more respect for the fans, the club, the coach and for themselves."

Next up for Napoli - who have slumped down to sixth in Serie A from third place - is a home clash with fourth-placed Fiorentina, whom they can leapfrog if they claim a rare victory.