Mikel John Obi has blamed himself and his Chelsea team-mates for the 2-1 defeat to Basel, saying that if the team do not improve they are capable of "losing to anyone we play". Chelsea took a first-half lead through Oscar but were unable to hold on, with José Mourinho questioning the "maturity and personality" of his team – a sentiment with which Mikel appeared to concur.

"It's a very bad result for us," the midfielder said. "We knew the kind of team we were playing against. We knew how good they are on the ball and what they can do when they have the ball. The manager spoke about how we had to put them under pressure from the first half, the first minute, and then they don't have a chance to win here. We didn't do that.

"It's very disappointing, especially for our fans, the way we lost the game. I am disappointed about it. Coming from another defeat at Everton, we wanted to use this game to put things right, but we didn't do that."

Chelsea travel next to Steaua Bucharest – a game which Mikel believes now has greater import if they are to qualify for the knockout stages of the Champions League.

"We have to put things right in the next game and put ourselves in the position of qualifying from this group. I think with the calibre of players we have here we shouldn't be afraid of anyone. But if we play the way we did today we have a chance of losing to anyone we play. We go back to training and look at the things we have done wrong and try to put it right."

The loss to Basel comes nearly six years to the day since José Mourinho was dismissed by Roman Abramovich following a 1-1 draw at home to Rosenborg. It's the kind of synchronicity Mourinho and his team are sure to want to ignore.

"I think we have had a bad start to the Champions League," said Branislav Ivanovic. "But this is just the first game and we have to stand up and show character in other games.

"Their goal changed the game. We started to go forward a lot and we opened the space for the second one. We don't usually concede from set pieces. There are still things we can improve and do better. Basel played really well. They played as a team tonight and for us it was a difficult game but we have to look forward."