Tipped him to be a Manchester United player next season in a couple of Van Gaal and dutch player topics over the last months.
22 year old Left footed centre-half who can also fill in at left back. Was a favourite of Van Gaal during the qualifiers. I'd say there's a big chance he'll play in the Holland defense in Brazil. Benfica tried to sign him last winter.
He's comfortable on the ball, pretty good passing. He's big, strong, not the fastest, but not slow either. His heading has to adapt to the Premier League, but he's a natural defender. Has had his ups and downs at Feyenoord, but age and all other things considered, he did very well there. Looks like a potential Benfica/Tottenham player at least, he might become even better over the years.
Will be interesting to see if Van Gaal takes him with him to United. He is available on the cheap (max 10 million pounds I'd say), has international experience, would be the left footed player in defense we almost surely going to get. Considering his age and the fact that he has played a lot of matches professionally already, I imagine him having no problems playing second fiddle behind Jones, Smalling, Evans, or filling in as a second or 3th choice left back.