Roberto Di Matteo: Chelsea have the quality to shock Barça and reach Champions League final

Chelsea manager confident of defending 1-0 lead against Barcelona at Nou Camp tonight

Roberto Di Matteo said last night that he believed his Chelsea team have the potential to win the Champions League this season, as they prepared to defend a one-goal lead tonight in the second leg of the semi-final against Barcelona in the Nou Camp.

The Chelsea caretaker manager has been reluctant to look beyond the next game during his team's unexpected run in the competition since he took over on 8 February, but he said that they had the capacity to confound the European champions. Di Matteo admitted that he felt his team would have to score again tonight if they were to have a chance of reaching the final on 13 May.

Di Matteo said: "I think we do have the qualities within this team. I think we need away from home, as we've seen in the past, a bit of luck to be able to do well in a competition like this. But certainly the quality and the squad we have at Chelsea is very good."

The big news for Barcelona was that Lionel Messi has recovered from what manager Pep Guardiola called a "gastric problem". The Argentine, who has scored 63 goals this season, missed training on Sunday but took part in the session at the Nou Camp last night. Gerard Pique is due to come back to the team after successive defeats for Barça in the first leg and against Real Madrid on Saturday.

Late in his press conference last night, Guardiola lost his patience with criticism from Spanish reporters about his selection of Cristian Tello and Thiago Alcantara in the defeat to Real. There had been particular scrutiny for Tello, 20, who was judged to be out of his depth in the 2-1 loss.

Before ending the press conference abruptly, Guardiola said: "Please, Cristian was the best player we had the other day. You can attack the veterans but not the young players. You attack Cristian? Analyse, don't criticise me. Most of the dangerous chances were created by Tello."

Di Matteo is expected to go with the same side the beat Barcelona six days ago. "Ultimately, Barcelona will create chances against every team they play against," he said. "We'll have to try and score a goal, for sure, but we must also limit the number of chances they can create against us."

Petr Cech, the Chelsea goalkeeper, said that his club were confident in the selection of the relatively inexperienced Turkish referee Cuneyt Cakir, who has only officiated in Uefa competitions for four seasons. It is the biggest match of Cuneyt's career so far and given the performance of Tom Henning Ovrebo in the semi-final between these two teams three years ago, there will be considerable focus on him.

Cech said: "The referee can be a big part of the game. You could see that in the past. There were great games between us and Barcelona but there was controversy which was a shame, overshadowing the great games on the pitch. We have an experienced Turkish referee. If you have experience of refereeing Galatasaray and Fenerbahce in the Turkish league, a game between Chelsea and Barcelona should be fine. The referee will have the same professional approach as we had in the first game, which was without controversy."

The issue of Didier Drogba's play-acting looms large over the game. Pique said he did not agree with the assessment of his former United team-mate Wayne Rooney, who was critical on Twitter of Drogba's tendency to go to ground during the first leg. The Barça defender claimed there was no doubt in his mind Drogba would only go down if injured, although his comments had the effect of once again highlighting the issue.

"Everyone plays the way they see fit," said Pique. "I don't know if Drogba was faking injuries. I don't think we can criticise him for that, I believe in Drogba and in his honesty. I believe that every time he fell down, it was because he was in pain. I don't think Drogba was trying to fake it or dive.

"I've faced him many times. The last I can remember was in 2009 and he's one of the best strikers I have ever seen. He's playing at a great level once again. It's not easy to score goals for so many years."

Pique prompted suggestions that he would be offered some advice from another former United team-mate when he said he had been contacted by Rio Ferdinand. "He sent me a message today telling me that he wants to talk to me."