Messi comeback possible as Barcelona launch Champions League charge

Messi, who has missed the beginning of the season with a calf injury, was named in Barcelona's squad for Tuesday's Champions League opener, though it remains unclear whether the Argentinian will play.

"We will decide tomorrow. For the last week we have been unsure whether he will be able to play, but he has trained two or three times and made a good impression. We will see," said Valverde at a press conference on Monday. 

The Barcelona coach refused to say whether 16-year-old Ansu Fati, who became the club's youngest ever goalscorer earlier this month, would break another record by becoming the youngest ever Champions League debutant on Tuesday.

"If he plays, then it will not be because of the record," said the coach.

Valverde said that his team were looking to put the past behind them after their dramatic semi-final defeat to eventual winners Liverpool in last season's Champions League. 

"If you have one bad day, you can be knocked out of this competition. We lost just one match last season, but it was a decisive match," he said, adding that Barcelona wanted to go further this year than they had in the past two seasons.

Yet Marc Ter Stegen, Barcelona's German keeper, who played under current Dortmund coach Lucien Favre at Borussia Moenchengladbach earlier in his career, warned that Dortmund would provide a tough first test. 

"Lucien Favre is one of the best coaches I have ever worked under, and he will have thought of a way to hurt us," said the German.

"It is always difficult to come here, and we always struggled here with 'Gladbach, but we will try to win and get a good start to the competition."

"It is a spectacular stadium and the supporters are always crazy, but we will try not to be influenced by that."

Barcelona have conceded six goals in four games this season and are yet to win away from home. 

"We are conceding a lot of goals at the moment, we have to accept that and try to improve," Ter Stegen

"Some of the mistakes we are making are easy to correct."