Andreas Hinkel has told his Celtic teammates not to be taken in by the weighty reputation of Barcelona, if they want to progress in the Champions League. The Germany player picked out the decline of Ronaldinho as an example of how the pursuit of excess, rather than success, has made the Spanish side vulnerable.

The Brazil player is not even certain of starting when Barcelona come to Celtic Park on Wednesday for the first leg of the last16 encounter, because he has been limited to substitute appearances after a dramatic fall from grace when Frank Rijkaard left the gifted forward out his squad after Ronaldinho’s weight ballooned.

Hinkel is not eligible to play for the Scottish champions because he has already played in the Champions League this season with Seville, before his £2.1 million transfer in January. He moved to Spain in the summer of 2006, just weeks after Barcelona paraded the European Cup in their city after defeating Arsenal in the final but says that Ronaldinho is now a shadow of the player he was.

“I don’t know the situation at Barcelona but a few years ago, Ronaldinho was a far different player and he had another body,” Hinkel said. “If you look at the pictures of a few years ago and compare them with now, it is another Ronaldinho. He is still a very good player but he needs greater fitness. Not every player in the world can be as good as Ronaldinho, but every player can be stronger and fitter. That is important in football.”

Hinkel says that his former coach for the German national side, Jürgen Klinsmann, told the squad ahead of the 2006 World Cup finals, to forget about trying to match Brazil’s individual talents and work instead on their collective strength, a philosophy that took Germany to the last four, while Brazil went out in the quarter-final stage.

“Jürgen said that we could not play like Ronaldinho, or other top players from South America, but we had to be fit and run and play for 90 minutes like a team, and then anything is possible. Germany beat Argentina. Football is not like freestyle soccer.

“I played against Ronaldinho in a friendly in 2005 when Germany drew with Brazil in Berlin. He shields the ball very well.”

Hinkel knows that Barcelona have largely replaced the reliance upon Ronaldinho with one built upon the gifts of Lionel Messi, but insists fear cannot be part of Celtic’s make-up on Wednesday. “If you want to beat Barcelona, you have to play at the highest level, 100 per cent. You have to be concentrating 100 per cent in every situation. Just one small mistake is enough for them. “Messi is a very good player. He is one of the best in the world. He has so much speed with the ball. He is unreal over the first few metres. You have to play smart against him, especially at the Nou Camp. Maybe it will be different here. Barcelona keep the ball so well at home and you spend 70 minutes chasing it, and then you are tired. I went to the Nou Camp twice with Seville and that is what it is like.”

However, Hinkel believes that Celtic have their own secret weapon that can tire out Champions League opponents in the east end of Glasgow: the Celtic Park pitch. “The pitches in Scotland are much softer than the ones in Spain, or even Germany,” the 25-year-old right-back said. “My muscles have been really tired at the end of games, after 70 minutes. You saw it with Bayern Munich when they faced Aberdeen. I played on the Aberdeen pitch a few days earlier with Celtic and I was struggling at the end. Maybe Barcelona will find it a problem.”

Hinkel pointed to the fact that Celtic have profited from late winners against AC Milan and Shakhtar Donetsk in other Champions League home games this season. “I spoke to the players when I came to Celtic and asked why they got so many late goals. I think the pitch is a part of the reason and the players also said it was the crowd. The atmosphere is special and the fans really push the team on.

“I am sad that I am going to miss this game. It is a big match but I knew before I came that I could not play because I played in the Champions League for Seville. I think Celtic can win on Wednesday. They have beaten all the top European teams at home. It will be difficult to get into the next round and there is another match to play in Spain. We need to get a result here but we have a chance.

“I know Barcelona are not playing well this season but it is still a great team. One player can decide a game and when you have so much quality in the team, you only need to play at 80 or 90 per cent.”