The 25-year-old Italian international of Argentine descent has been roundly criticised by the Espanyol supporters and Spanish media.
"First of all I want to apologise to the fans for the way and the speed in which I left Espanyol. To clear things up I will say that I went the wrong way about it, to avoid talking and saying things in haste that I would later regret," he told Mundo Deportivo.
"Like all footballers I am a professional and have a responsibility to my family. Besides, before the offer came in I asked Espanyol if they could recognise my contribution a bit more, being aware of how the club was when I joined.
"I am not ungrateful, but that said the club's response was clear: they said no. Then I proposed something else to them to see if it was acceptable... Quite simply that my colleagues and I were due to be paid daily over the course of the season, something that didn't happen, and we were all owed money.
"I wanted to assert my strength as one of the leaders of the group, but again the club's response left me cold. They told me they could afford to pay me daily but not my colleagues. I thought that was outrageous and shameful. How was I going to earn money daily when my teammates were not? I felt embarrassed. That was one of the things that made me realise I would have to go if an offer came in. It just seems incredible, but I swear there were players who could not pay the rent on their houses. I've never seen that at any of the clubs I've been with."