The Italian believes that he did not have the reputation needed to be accepted at San Siro, and did not receive the backing of the board during his spell at the club
The 54-year-old only lasted a handful of games at the Lombardy club before being sacked and replaced by Claudio Ranieri in September 2011.
However, he feels that he was not allowed to make the signings he needed to, to turn the Nerazzurri into a competitive force, and also added that his tactical changes were rejected by the squad.
"Inter are getting a competitive squad this year," he told Tuttosport. "They are signing key players, unlike last year when they were signing extras.
"Now I see [Giampaolo] Pazzini, one of the main sources of my unhappiness, out of the squad. I also see Palacio. I see a three-man defence, which is everywhere now - Juventus, Napoli...
"I also see that Inter finished sixth in the end, and they tried to cover it up and fix it. I do not think that can be considered a reasonable finish.
"I do not think I would have done the same. I don't think I would have ended on 58 points.
"Is there any regret? I probably didn't arrive at the right time or with the credibility I deserved."
Inter set up a Europa League play-off tie with Vaslui by beating Hajduk Split 3-2 on aggregate, despite a 2-0 loss to the Croatians at San Siro on Thursday.