Chelsea goalkeeper Thibaut Courtois has urged his teammates to bounce back from their defeat against Roma with a strong performance against Manchester United on Sunday.
Antonio Conte's side dropped to second in Group C after losing 3-0 to their Italian hosts on Tuesday night - Stefan El Shaarawy opened the scoring inside the first minute.
El Shaarawy's second strike was followed after the break by Diego Perotti's goal as Chelsea were humbled.
"We have to fight back against Manchester United," Courtois told BT Sport. "Sometimes last season I had nothing to do in a game, sometimes I'd have one save to make.
"We have to react on Sunday as [Tuesday night] was a bad image of ourselves. I thought we played well in the first half but in the second half we seemed to drop our fighting spirit and I don't know what happened.
"It's hard to say what the problem is. This season every game is a hard game. We have to find that balance again."
Chelsea's clash with United comes as Jose Mourinho's men secured their fourth win from as many games with a 2-0 win over Benfica.