Lazio president Claudio Lotito has said he received "between 50 and 80 death threats" after the sale of Hernanes to Inter Milan on Friday.
Fans congregated outside Lotito's home on Friday to protest against the departure of the Brazilian playmaker and call for him to quit.
The president, who took up his role in 2004, has come under increasing pressure this season, with poor results leading to calls for him to step down.
But the sale of the popular Hernanes has seen the feeling against Lotito increase, and Gazzetta dello Sport reported him telling a Lega Serie A meeting on Monday: "I received between 50 and 80 death threats yesterday.
"The fans felt they were part of this club -- but now they've misinterpreted their role."
Hernanes had called on the club's fans to lay off Lotito following his move, saying leaving had been his choice and he had not been forced to go. to Inter, saying that it was always his choice to leave.
And Lotito echoed those words, saying: "Hernanes decided to leave and he'd already reached an agreement with Inter -- so what was I supposed to do?"
"If he'd stayed, he would only have been unhappy. If you want to leave, you've just got to say so. Hernanes is a great player and a great man but Lazio are not second to anybody, apart from Juve when it comes to revenue."
Lotito also lamented the difficulty in attracting players to his club, even though they are still in the Europa League and only four points adrift of the top six in Serie A.
"[Fabio] Quagliarella turned us down, [Jonathan] Biabiany was offered to me by [Parma president Tommaso] Ghirardi and we had an agreement, but the player turned down a lucrative offer,” he said.
Meanwhile, Lazio coach Edoardo Reja has said he wants Napoli to make life difficult for their city rivals Roma in the Coppa Italia this week.
A 1-0 defeat to the Neapolitans at the Stadio San Paolo last week saw cup holders Lazio eliminated at the quarterfinal stage. Had they progressed, they would have faced Roma three times in the space of the week, with the two legs of the semifinal tie sandwiching a Serie A derby next Sunday.
Now Reja wants Napoli not only to beat the Giallorossi on Wednesday night but also to give them the toughest 90 minutes possible.
"I hope Roma really, really struggle against Napoli, and it wouldn't be bad if somebody picks up an injury either," he told RAI television after his side's 2-0 win at Chievo on Sunday.
Reja knows his side will go into the Eternal City derby as underdogs, with 19 points separating the two sides in the table.
And the frustrated coach echoed the thoughts of his president when he said: "It seems like the only thing you can win with Lazio is the Coppa Italia. Clearly, people prefer to stay where they are and not play rather than come here. The truth is, we made bids for about ten different players and nobody accepted to come to Lazio.”