Chelsea manager, Maurizio Sarri, has said that they risk a "disaster" against Manchester City in the Carabao Cup final on Sunday, if they repeat their nervous start in Thursday's 3-0 win over Malmo FF.
Second-half goals from Olivier Giroud, Ross Barkley and Callum Hudson-Odoi, sent Chelsea through to the Europa League round of 16 with a 5-1 aggregate victory.
But the opening 45 minutes yielded few Chelsea chances and plenty of nervy moments, as Malmo pressed high early on.
Speaking after the game at Stamford Bridge, Sarri warned that similar mistakes against City at Wembley, could result in a humiliation reminiscent of their historic 6-0 thrashing at the Etihad Stadium earlier this month.
"I think that we played the first 30 minutes without confidence.
"Nervous. We were unable to move the ball very fast. We were in trouble on their pressing. Then a little bit better in the last 15 minutes of the first half and then, after the first goal, very well.
"We started to move the ball very fast and with confidence, very well. But it wasn't easy for us to play this match, so I can understand my players for the first 30 minutes," Sarri said.
Asked what will happen if Chelsea make similar errors against City, the Italian replied: "A disaster, of course. But I am worried about the first 30 minutes only for the offensive phase because we cannot play our football without confidence. But the level of application and attention was good, also in the first 30 minutes."