Former Spain striker Raul has admitted that he is concerned by the current group of forwards in the squad ahead of the World Cup.
Diego Costa has been battling a hamstring problem in recent weeks, while Fernando Torres and David Villa both struggled to hit top form in the latter stages of the season with their respective clubs, and Raul believes that Vicente del Bosque could decide to use a system without a recognised striker.
"David Villa and Fernando Torres were not inspiring for their clubs. We might see Del Bosque switching to 4-6-0 again," the 36-year-old told reporters.
"If it helps scoring goals, there will not be any problem. But if it fails, he will not be spared. That's the life of a footballer or a football coach. One bad day and supporters will be after you.
"To defend a World Cup is tougher than winning it. Whether Spain can do it is the question Spanish fans are asking. Vicente del Bosque knows his team and the formations he needs."
Cesc Fabregas was used in an advanced role during Spain's successful Euro 2012 campaign, and he could be asked to adopt a similar position in Brazil.