Manchester - Just a month into the season, Manchester City is already facing a game of huge significance in the defense of their Premier League title.
If Manchester City loses at home to early leader Chelsea on Sunday, September 21, the champions will be eight points behind their biggest rivals for the championship after five matches.
And that will be a sizeable gap considering the strength of the squad that Jose Mourinho has built for this season.
Manchester City's start to the season is giving ammunition to the critics who questioned whether the club's off season recruitment was good enough.
While most of its rivals brought in exciting attacking talents for the new season, City chose to bolster its squad with extra defenders and a tough-tackling defensive midfielder, purchases that were sensible but hardly set the pulses racing.
The champions are also down to three strikers after selling Alvaro Negredo on the final day of the transfer window.
Manchester City's 1-0 loss to Bayern Munich in the Champions League on Wednesday extended its winless run to three games ahead of the visit of Chelsea, which did the double over City last season.
Some early-season pressure would come on City manager Manuel Pellegrini if he fails to mastermind a victory over Mourinho, whose tactics were perfect in Chelsea's 1-0 win at Etihad Stadium in February.