Carlo Ancelotti has admitted his Chelsea side must win 13 of their remaining 16 games if they want to defend their Premier League title.
Manchester United stretched their club-record unbeaten start to the season to 22 games on Saturday to move 10 points clear of Chelsea, but Ancelotti is convinced they will not emulate Arsenal's 2004 'Invincibles'.
"I think it's impossible because if we want to come back to fight for the title we have to beat Man United," Ancelotti said.
As well as beating United home and away, Ancelotti admits Chelsea must also win their head-to-heads with third-placed Manchester City and fifth-placed Tottenham at Stamford Bridge in the second half of the season if they are to defend their crown.
