Joaquin claims his "state of mind" makes him useless to Fiorentina and he does not understand why they are keen on keeping him.
Fiorentina winger Joaquin confirmed on Monday that he wants to leave Italy and return to boyhood club Real Betis.
Joaquin posted on Instagram "my decision is made, I just want to go home" as he attempts to force through a transfer to Betis, with Fiorentina so far denying him that move, with president Andrea Della Valle having claimed the 34-year-old is "a key part of our project".
After two seasons with Fiorentina, Joaquin claims he is not happy in Florence and does not understand why the Serie A club are blocking a transfer.
"I want to return to Betis, I can no longer play for Fiorentina," the veteran attacker told Firenze Viola.
"Things are very bad at this time. I would have never thought I would be going through a moment like this near the end of my career.
"I don't understand why they [Fiorentina] are doing this. There is a lot of talk about me, but there is little truth in what is being written.
"I was put up for sale last season, when I was training away from the first team. I don't know why they have changed their mind now.
"I don't know why they are doing this to me, the team and my team-mates. Even the Viola fans agree with me.
"When fans stop me, they say 'it's understandable you want to go home'. I can't understand why Fiorentina can't understand this as well.
"I have made my decision. Nobody can decide for me and I have decided to return home, to return to Seville where I am happy.
"They told me I was for sale and I have decided to return to Betis. My heart is in Seville and I can't play with this sentiment.
"I can't help my team-mates with this state of mind."
Joaquin has made 49 Serie A appearances for Fiorentina, with the Spaniard starting 19 matches.
The former Spain international joined Fiorentina from Malaga, having also previously played for Valencia.
Joaquin started his professional career with Betis B in 1999, before earning promotion to the first team for the 2000/01 season and left the club with 218 senior matches to his name.