Spain coach Vicente Del Bosque has said today that his titleholders must be on their guard as they prepare to face France in Saturday's UEFA EURO 2012 quarter-final showdown. The two countries met in the last-16 at the 2006 FIFA World Cup™ and the French won, since when Spain have been unstoppable. But with the French back in the groove more or less under Laurent Blanc after their mutinous 2010 FIFA World Cup showing Del Bosque warned the Spanish must not count any chickens - indicating they had been guilty of as much six years ago. "I retain an image of the 2006 World Cup. We under-estimated the French as they were getting on. It is a very Spanish trait not to pay attention to one's rivals," Del Bosque told Onda Cero. The Spanish were putting together a young and exciting team in 2006 - under coach Luis Aragones and they would go on and win EURO 2008 under his guidance and South Africa 2010 under Del Bosque - and the home media promised they would "send France into retirement." But Zinedine Zidane and company promptly won 3-1. Del Bosque maintains France were the strongest side in their Group D - even if they lost to Sweden and qualified behind England. "France were the most complicated opponents for us, the strongest in Group D. they have the ingredients of a strong team. Technically they are strong and very organised. I think they'll play like us - the French do not have any complex." Del Bosque said that the absence through suspension of defender Philippe Mexes "is an important loss but France have the Arsenal boy (Laurent Koscielny) who is very good." Del Bosque also said he did not intend to make major changes to his team for the match which will pit against each other two nations who will also meet in qualifying for the 2014 FIFA World Cup. FIFA .