Alonso said, "Last season we saw that you never know what's going to happen in football but this is the first game on a long road to the final. It's a long way to Paris and if we want to get there again, we must only think about this match on Tuesday night. If we think only of retaining our title, we can come unstuck."
And Alonso added that he was well aware of what the match would mean to the Betis team and fans, as they play their first ever Champions League match.
"The fact that this will be the first ever Champions League game for Betis and it's against the current European Champions will maybe lift the Betis players, but we will be careful and we've prepared as well as we possibly can for this match," he said.
He added, "We know they are very quick in attack, we know they have great wingers and we know they are a strong team at home. The fact that the manager and some of the players know a lot about Betis is helpful for us.
"For me personally, it is great to come back to Spain but I'm here for a football match and we want all three points," Alonso concluded.
