Jose Mourinho’s Chelsea will begin the 2014/15 Premier League campaign with title aspirations but the manager knows there is little margin for error.

Chelsea finished third last season, despite beating champions Manchester City and runners-up Liverpool both home and away, as defeats to Aston Villa, Sunderland and Crystal Palace proved costly.

“Next season will be very, very difficult, even more so (than last season),” Mourinho said.

“I know Chelsea will be better, but maybe the other teams will be better too, so it will again be the kind of league where you don’t know if you’re going to finish first or finish sixth.

“In this moment I have to think and say we want to finish first.”

For the first time in 14 years Chelsea will begin a season without Frank Lampard in the squad after the 2001 signing from West Ham, who went on to become the club’s record goalscorer, left at the end of his contract.

After eight years at Chelsea, left-back Ashley Cole is also a free agent, although yet to confirm where he will play next season.

The arrival of striker Diego Costa from Atletico Madrid is imminent to join his fellow Spain international Cesc Fabregas in a continuation of the evolution of the squad.

“After 10 years of titles and great moments, this is a moment to rebuild again, because teams don’t last for ever,” Mourinho added.

“Clubs yes, but not the teams. In the same club you have to build another team.

“That’s what we are doing, and for sure the results will come.”