The former Tottenham midfielder wants the South Korean to stay on at Hamburg, despite several European sides looking to lure him away from Germany
The South Korean, who has scored nine goals in 21 appearances, is reportedly a target of several European clubs who are battling to attract the young striker’s signature.
But the ex-Tottenham play-maker believes that Son should stay with the German outfit, highlighting the promise of first-team football
“I think for Sonny, it would be better to stay here [at Hamburg] for now," Van der Vaart told reporters.
"And I'm not just saying that because the boy has been in outstanding form for us. It's the first very good season in his career, he doesn't have to become jumpy and make a switch.
"At the biggest clubs, you can quickly end up on the bench, especially as a young player."