Robin van Persie will be substituted again if he isn't up to standard, claims Louis van Gaal

Robin van Persie will be substituted again if he isn't up to standard, claims Louis van Gaal Louis van Gaal claims Robin van Persie must stay fit and be on top form to maintain place in Holland attack Holland boss replaced striker with 15 minutes to play in win against Mexico Manchester United striker expected to start in World Cup quarter-final with Costa Rica Nigel de Jong not expected to recover for last-eight tie following groin injury Holland and Manchester United manager Louis van Gaal has told his star striker Robin van Persie that he will be sacrificed if he isn’t fit enough or playing well enough. Van Gaal and his captain Van Persie are thought to have a unique bond that United fans will hope can be replicated when the veteran coach starts life at Old Trafford after the World Cup. VIDEO Scroll down to watch Robin van Persie enjoy kick-about with daughter Dina Hauled off: Louis van Gaal shakes Robin van Persie's hand after surprisingly substituting the striker in the last 16 World Cup win over Mexico Super sub: Klaas-Jan Huntelaar replaced Van Persie, assisting one goal and scoring another to complete a late turnaround for Holland Good relationship: Despite the substitution, Van Gaal and Van Persie have a harmonious understanding within the Holland national side Afterwards, Van Gaal was asked if Van Persie was injured and said: 'No. Doubt: Nigel de Jong limped off during the win against Mexico and is now a doubt to face Costa Rica in the quarter-finals Underdogs: Costa Rica have stunned many to reach the quarter-finals after defeating Greece on penalties Van Gaal has denied that his team have a straight forward route to the last four, even though quarter-final opponents Costa Rica are ranked 28 in the world and had to play extra time against Greece yesterday.