Maurizio Sarri admitted on Friday Chelsea face a “very difficult” task to reach the levels of Premier League pacesetters Liverpool and Manchester City as he prepares his team to face Manchester United.

The Italian believes the Blues must close the gap in a maximum of two seasons, though his position at Stamford Bridge remains under threat.

Chelsea head to Old Trafford on Sunday, where the winners will take a significant step towards a top-four finish to secure Champions League qualification for next season.

Sarri, 60, told reporters at his pre-match press conference the points tallies earned by Liverpool and Manchester City - both closing on 90 points - were “incredible” and said he wanted the chance to elevate Chelsea to that level.

“It’s incredible because Manchester City, in the last season, gained 100 points,” said Sarri. “To gain 100 points in the Premier League is really incredible, really very difficult.

“In this season, two teams, I think they will finish with about 97, 96, 95 points. That’s incredible. It’s very difficult to cover the gap. Really very difficult. We need to work. We need to improve.

“Of course, this one is the third season of [Pep] Guardiola at City, and the fifth I think of [Jurgen] Klopp at Liverpool [Klopp is in his fourth season at Anfield]. So it’s a long way [to go]. But in one or two seasons, we have to recover the gap.”

Sarri said his team, currently in fourth spot in the Premier League, are improving despite taking just a single point from their past two matches.

“Tactically, we are improving,” he said. “Mentally, too. Because two or three months ago, at the first difficulty in a match, we were not able to fight or react.

“Now my feeling is different. Now we are able to fight and react. But of course to recover the gap will be really very difficult for us, but also the other teams.”

He said Chelsea had to improve their away form at their top-six rivals after league defeats at the hands of Arsenal, Tottenham, City and Liverpool this season.

“We need to face difficulties because for sure against these teams away you have to face difficulties,” he said.

“We need to be able to stay in the match in the 10 minutes of difficulty. Sometimes in the second part of the season we lost the match in 10 minutes.”

And Sarri said he was surprised Eden Hazard did not feature in the Professional Footballers’ Association team of the year despite an outstanding season for Chelsea.

“Eden deserved to be in the top XI of the Premier League, but I also think the table is clear,” he said.

“There is City, there is Liverpool, and then the other teams. The vote was influenced by the table.”