Why would he turn down Man Utd?
If they came in for him, he'd be off there. It just so happens that Man Utd, when conducting their transfer business, do so in a respectful matter, rather than Liverpool's sly approach. But they could have their pick of any player in the Premier League, and have the finances to better anything Liverpool could offer. Man Utd is a bigger club than Liverpool, so of course VVD would opt for them. But as Man Utd have already spent big on a defender, they're not in the race.