"At the moment, this is the most important match of the season. I'm not just talking about the money, but also about winning the Champions League again," he said.
"If we want to play in the group stages, then this game is really important. In the Premiership, you can not do well for a few games and then win 15 games in a row. You can't do that in Europe, though.
"Maybe if we reach a semi-final or a final then perhaps that might end up being the most important game, but we need to win this tie to progress in the Champions League.
"We must wait to see where the second leg will be. The most important thing now, though, is to prepare properly for the first leg and if we can win by a few goals at Anfield then where the second leg is played won't matter as much.
"We know we must score and do well on our own ground, it will be vital to do that."