Cape Town - Chelsea manager Maurizio Sarri says his side's defending against Tottenham Hotspur on Saturday was a 'disaster' and he emphasised much improvement was needed.
Spurs raced into a 2-0 lead in the first 20 minutes and would eventually emerge 3-1 winners in the Premier League contest in London.
The score-line could have been even greater had the likes of Harry Kane and Son Heung-min not spurned very good chances in the encounter in the English capital.
As such, Sarri, who sees his team's 18-match unbeaten run come to an end, says changes are needed: "We have to try to do something, because the defensive phase today was a disaster.
"Not only the defensive line, the defensive phase, the offensive players pressed very badly. The midfielders did not defend very well, and the defensive line as a consequence was a disaster.
"We were surprised because today they played with the 4-3-1-2. But after five minutes the situation was very clear.
"In the first 25 or 30 minutes, we had a lot of problems getting the ball out of our half. Against Tottenham that is very dangerous to lose the ball in your half, because with their short counter attacks they are maybe one of the strongest teams in Europe."
Regarding a penalty appeal which was not given early in the game when Eden Hazard went to ground, the Italian: "I don't think [it would have changed things]. For 90 minutes there was a difference, so I don't think so.
"I have to think and study the other 90 minutes, not only one action. I don't know if it was a penalty or not. I saw it from 50-60 metres. From the bench, my position, I thought it was a penalty, but I have to say that Tottenham won very well."