Mancini had growing tension with the club over transfer strategy, which reached a head when he terminated his contract by mutual consent just two weeks before the start of the Serie A season.
“We had no intention of terminating the rapport with Roberto early,” Ausilio told the Corriere dello Sport.
“This separation was not determined by results and was a complete surprise, even if in football these things can happen. We still have a splendid rapport with a Coach and a person who over the course of his two experiences at Inter did extraordinary things to help the club grow.
“Mancini laid the foundations for a winning future and now De Boer has to continue along this path.”
Former Ajax boss De Boer was for many an unusual pick for the Nerazzurri, though he had previously been linked with Lazio.
“It wasn’t a decision we planned in advance, as it all happened so suddenly. Mancini was talking about a contract renewal and we weren’t expecting him to leave.
“We discussed the situation with (President Erick) Thohir and Suning Group, then decided to go for De Boer. He was the only candidate, the only one we contacted.
“I have been impressed by his determination and ability to quickly settle into Inter and Italian football in general. He knows what the Nerazzurri represent and has been a top level player winning trophies with Barcelona and Ajax.
“He was not surprised by the difficulties of Serie A, even if he perhaps didn’t know the details of all the opposition teams. In the course of a month he’s been able to give interviews in Italian, something that others were unable to do in the past.
“In September, after the break for international duty, I saw a team with a tactical identity.”
There have been some shaky results so far, above all the two consecutive Europa League defeats to Hapoel Beer-Sheva and Sparta Prague. Will Inter have the necessary patience for De Boer to find his feet?
“All Coaches are given faith, especially ones who only arrived in August.
“Last season Maurizio Sarri initially had difficulties at Napoli, but the club gave him the necessary time to work on his ideas and now Napoli both get results and play good football.”