Chelsea manager Antonio Conte has admitted that his side must improve their teamwork on the field if they are to avoid a repeat of last season's dismal title defence.
The Blues finished down in 10th place in the Premier League table last time out, leading to the arrival of the Italian this summer to bring a fresh feel to the club.
Conte's charges looked completely disjointed at times during their 3-2 defeat to Real Madrid on Saturday evening, falling three goals behind in a poor first-half showing at the Michigan Stadium.
Speaking to reporters after the match, the former Italy and Juventus manager said: "I know it's not easy to play this game against another great club after only two days of rest, and after a flight of four hours and a half. I know this because I knew the team was a bit tired.
"But today, I think that this match is very important for us because after this game it's clear that we have to work together always - without the ball and with the ball - because if we think that we can't work together when we don't have the ball, it's not possible for us.
"It's not possible, and we risk to repeat a bad season. Today, I think we weren't a team in defensive situations. It's important because in the last game, I appreciated a lot our defensive situation and I told also that we can improve when we have the ball. Today, [we were] better with the ball, but bad without the ball."
Eden Hazard came off the bench to score two goals for Chelsea in front of 106,000 spectators on his return to club action.
