Sir Alex Ferguson believes it would constitute "an astonishing decision" if Chelsea chose to relieve Carlo Ancelotti of his duties at the end of the season, with the Italian set to discuss his future at Stamford Bridge in the week after the final round of Premier League fixtures.

Ancelotti takes his side to Old Trafford on Sunday aiming to extend Chelsea's title defence by becoming the first opposing team to win at Manchester United this season. Victory would see the visitors leapfrog Ferguson's side to go top with just two fixtures to play, yet even the retention of the championship is not guaranteed to keep the Italian in his job in south-west London.

Roman Abramovich – dismayed by a mid-season slump that saw 10 points gleaned in 11 matches and United eliminate Chelsea from the Champions League at the quarter-final stage – and his chief executive, Ron Gourlay, are to review Ancelotti's position with the manager expecting talks to take place immediately after the final-day fixture at Everton. "We will see after the end of the season, maybe the week after," he said. "That's what they've said to me. That's when we will speak about the future."

Asked whether it was really possible for a manager, who had claimed a league and FA Cup Double in his first season in the English game, to be sacked within hours of claiming the title, Ancelotti added: "In Italy, it's happened. I would like to stay. But I am very quiet and calm about it. At the end of the season, the club will take a decision. If they consider my job to have been good, I will stay. If not, they can change. But, for now, the problem is not whether I stay or if I go. It's whether we win at Manchester [United]."

His anticipated departure would amaze Ferguson, who claimed his first Double in 1994 but won no silverware the following year, prompting the sale of high-profile players such as Paul Ince, Mark Hughes and Andrei Kanchelskis.

"He has done well," the United manager said of Ancelotti. "I don't know where that atmosphere [of uncertainty] around him comes from, but it always seems to be there. The rumour mill at Chelsea seems to be working overtime, but the guy has won two European titles, he has won the Scudetto, and the Double with Chelsea, so you cannot question that record.

"Being knocked out of Europe affected them, but I cannot understand these stories [that Ancelotti will be fired even if he wins the league]. It would seem quite an astonishing decision. It is the rumour mill that happens in football. It sometimes comes from agents, sometimes it comes from people inside a club. But he has held his dignity well, he really has, and I do not see why he should have to answer the question [about his future]."

Abramovich has long coveted the European Cup, a trophy he had come so close to claiming with José Mourinho, Avram Grant and Guus Hiddink in charge. The appointment of Ancelotti, who had won the competition twice with Milan, partly reflected that desire with the reality that Chelsea have lost all four knock-out ties – against Mourinho's Internazionale last season and Ferguson's United last month – under the Italian a source of intense frustration at Stamford Bridge.

Chelsea are expected to drop their £50m signing Fernando Torres to the bench on Sunday with the visitors all too aware that defeat would effectively hand the title to United. "They have an opportunity to win it against us, but we don't want to see the celebrations of United," Ancelotti said. "Maybe, if they really have to win the title, they will have to postpone the celebrations until the next game."