He said: "Getting through would be one of the best results in the club's history, considering the opposition we are up against and the calibre of player we are facing. We are playing against one of the best teams in the world.
"Barcelona don't have one or two world class players, they have six or seven so to get through would be unbelievable. It will be very tough, they stepped up a gear at Celtic Park and it was very tough to get the ball off them.
"But hopefully it will be different in the Nou Camp and we can get a bit of possession and get up the park. We have to go there and score a couple of goals which is easier said than done.
"Other teams in the La Liga can get results against Barcelona so I don't see why we can't get a good result. But although they lost four goals last night in the league against Atletico Madrid their main focus is on the Champions League and by the way they played in Glasgow it's going to be a very, very tough night.
"I'm as confident as I can be but I'm under no illusions, it's going to be a tough task ahead of us."