Fiorentina sacked manager Vincenzo Montella with a critical club statement on Monday, saying the move is "for the good of the club."
Montella had been under pressure after criticising the behaviour of some of the club's fans towards the end of the season for "ridiculing" his players.
A statement on the club's website confirmed that Fiorentina viewed Montella's statements as a breach of his contract, which had one year remaining.
"Fiorentina have interpreted the recent behaviour of coach Vincenzo Montella as the clear desire to break from a contract legitimately signed two years ago," a statement announced.
"It contains a clause which the coach no longer believes to be in his interest, but to which he agreed at the time.
"So, with great regret we must take note of the fact that there is no longer the relationship of trust necessary for the continuation of any relationship, and we are therefore forced -- for the good of the club -- to sack Vincenzo Montella.
Montella had also delayed on signing a long-term deal with the club, which issued a statement last week urging the coach to make up his mind.
Despite a fourth-place finish under Montella in Serie A this season, Fiorentina will look for a new coach before they begin play in the Europa League this summer.
"This sudden situation has obviously created organisational problems which we must resolve urgently," the club statement said
"We would have expected clearer, more respectful and less ambiguous behaviour from the coach, in respect of the shirt, the fans and the club which has given him so much."
Montella has been linked to openings at Napoli and AC Milan.