The Dutch club’s sporting director Marcel Brands has confirmed that they are keeping an eye on the 24-year-old and could move for him next month.
The Dutch international joined the Blues in 2013, but he has spent most of his time on loan spells. He had a short but successful spell with PSV during the second half of last season.
“We need to check with Chelsea,” Brands told Dutch broadcaster Omroep Brabant.
“The question is now with our technical staff.
“Of course he’s on our list, but we must also see if there is a spot for him at this time in our team.”