Chelsea manager Carlo Ancelotti is refusing to under-estimate Atletico Madrid even though the Spanish side have endured a poor start to the season.
The Blues face Atletico on Wednesday having beaten FC Porto and Apoel Nicosia 1-0 in their first two European ties of the season.
In contrast the Spanish side have taken only one point from their first two Champions League matches and have won just one of their opening seven La Liga encounters.
However, Ancelotti has warned his players not to take the game for granted, saying: "We have had difficult games in the Champions League.
"Porto, in the first game, was not an easy match because they have very good organisation.
"The same thing against Apoel Nicosia. Everyone thinks that playing in Cyprus is easy, but it's not. Football in Cyprus has improved. For example, the national team won 4-1 against Bulgaria recently.
"There are no easy games. We can play better in the Champions League, for sure, but at the moment it's important to win.
"We want to play our best in March and April when the matches are very, very important. Atletico have not started the season well, but they have a very good quality.
"In attack they have Sergio Aguero and Diego Forlan who are dangerous strikers. We have to pay attention to this.
"Aguero has fantastic quality and he can resolve the match with his quality. They're a good team but, at this moment, they haven't found a good disposition tactically on the pitch.
"I think that Atletico has a possibility to return to playing well because they have a lot of quality. Now, at this moment, for them it's not easy because Porto have also made a good start.
"But in these four games, they can still arrive at the top. It's a very important game. Not only to get back to winning ways after Aston Villa, but to stay top of the group and move to nine points. This will make the next three games in the group easier."