Barcelona v Chelsea: Roberto di Matteo says Blues must score

Roberto di Matteo says Chelsea must score to advance from Tuesday's second leg of the Champions League semi-final against Barcelona at the Nou Camp.

The interim Blues boss takes his side to the home of the defending champions with a 1-0 first-leg advantage.

Di Matteo said: "The tie is half-time, it's 50-50 - both teams still have the same chance to go through.

"I do think we will have to try to score. It will be difficult to just play for a goalless draw."

He will assess the fitness of striker Didier Drogba, who missed Saturday's game at Arsenal with a knee injury but trained at the Nou Camp on Monday night, before deciding on his starting line-up.

Chelsea have lost only once in 14 matches - a 2-1 defeat at title-challengers Manchester City - since Di Matteo replaced Andre Villas-Boas in early March for the remainder of the season.

The former Blues midfielder has also guided the team to an FA Cup final against Liverpool next month and now has the chance to lead them to only their second Champions League final.

"Barcelona will create chances against every team they play against us so we will have to try to score a goal but we have to also try to limit the chances they create against us," said Di Matteo.

Counterpart Pep Guardiola confirmed that his star playmaker Lionel Messi would be fit to play after missing training on Sunday.

Messi featured in training on Monday and Guardiola said: "Leo had a gastric issue, called the doctor and didn't train yesterday. But now he is OK."

Guardiola at times used forthright language following some persistent questioning in a prickly news conference.

He rejected the suggestion that Chelsea would have a fitness advantage given that only three of their team from the first leg played in the goalless draw at Arsenal on Saturday, while Barca were involved in a gruelling El Clasico defeat against rivals Real Madrid.

"It is not tired in the legs, maybe in the mind, but we are going to try not to be tired in our heads," he said.

"Anyway in this situation, the semi-final of the Champions League, it doesn't matter if we played three days ago or yesterday, we will be ready to compete to try to reach the final."

In six matches against the west London side as Barca coach, Guardiola has yet to record a victory, and he admitted: "They are a very, very strong team, it's a challenge for us, very, very tough, but we are ready to fight against them."

Meanwhile, Barcelona defender Gerard Pique has said he does not believe Drogba was trying to con the referee by simulating fouls in the first leg.

The Ivorian, who scored the only goal at Stamford Bridge, was criticised for some theatrical falls during last week's match but Pique said: "I believe in Drogba that, every time he fell down, it was because he was in pain, or he felt a kick on him.

"I don't think that, when Drogba fell down, he was trying to act or dive. If he keeps doing that, you might end up thinking that's the case but I believe in his honesty."

Barcelona have won the Champions League three times in the last six seasons, while Chelsea's only final appearance ended in a defeat on penalties to Manchester United in 2008.