Manchester United striker Robin van Persie has weighed into Stefan de Vrij's problems at Feyenoord.
The young defender has actually angered management for doing extra training on his own.
Holland captain Van Persie remarked to ANP: "I like the fact that such a young boy sees his shortcomings and wants to improve. He wants to be better and is doing something extra to make that happen. He should be applauded.
"I'll confess something. I still played football on the street in Rotterdam when I was playing in the first team of Feyenoord. I've never said anything about it. I was never injured. I also became not the worst footballer."
