Spain coach Vicente del Bosque believes goal difference could be a key factor in La Roja's qualification group for Euro 2012.

Speaking in a press conference, Del Bosque believe that his side need to rack up the goals in order to secure qualification.

He said: "Goal difference may be vital. The first thing we must do is win, but respect all opponents. It will be a demanding group, but above all, the most important thing that concerns us it to win.

"We have seen a few games of Liechtenstein. They are an organised team, who are strong physically. Any team with these qualities can be complicated."

The ex-Real Madrid manager said that his side will need to erase memories of their World Cup win and re-focus on their new challenge.

He added: "We can make a good team with the players we have here. We are ready for qualifying.

"We start from scratch as if we have not played in the World Cup and our singular goal is to reach the finals in Ukraine and Poland."