The head coach had dinner at the weekend with Agnelli and sporting director Fabio Paratici, in the wake of Saturday's 2-1 defeat to Hellas Verona.
"Following Maurizio Sarri's comments, Poste Italiane invites Mr. Sarri to dedicate a few minutes of his precious time to inform himself that Poste is the biggest business in the country, which is chosen by young graduates among the most attractive companies to work for".
Sarri, a 61-year-old former banker, took over from Massimiliano Allegri at the Turin club this season having previously coached Napoli and Chelsea. Sarri could lose his job if he fails to deliver the 10th Series A title in a row as Juventus is now stalked on nine.
In a news conference, he quipped: "If I hadn't wanted to be under scrutiny I would have applied to work at the post office".
'We were supposed to have dinner after the Fiorentina game, I was at Coverciano, and the president had commitments and so it was arranged for later.
One Juve insider said: "Andrea has never hidden his interest in Guardiola".
"It is normal that my work is always under scrutiny".
Juventus is second in the Serie A table on goal difference, Inter Milan is occupied the first position.
Juventus will face AC Milan in the first leg of their Coppa Italia semi-final on Thursday, with two Serie A games to come before they return to Champions League action in the last 16 against Lyon at the end of the month.
'We are on target to reach the objectives we set out at the start of the season.