Chelsea boss Thomas Tuchel admitted he is concerned about his side's last three performances after repeatedly letting their lead slip and insisted they must return to basics.
The Blues fell to a 3-2 defeat to West Ham in the Premier League last Saturday after taking the lead twice before the break through Thiago Silva and Mason Mount.
It was the first time Chelsea had conceded more than one goal this season and the result knocked them off the top of the table.
The German's side went on to concede three more midweek in a rollercoaster 3-3 draw against Zenit St Petersburg in the Champions League.