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Jan Vertonghen's agent, Tom De Mul, has said the defender may yet sign a new contract at Tottenham Hotspur.
Vertonghen is in the final months of his deal at Spurs, so he could leave for free at the end of the season.
"We currently have no agreement [with Tottenham], but I do not rule anything out.
"We consider everything. There is a lot of interest for Jan, certainly as a free agent, but Tottenham also remains an interesting option for us. The door is still open."
The 32-year-old has been a stalwart at the back for the Lilywhites since his arrival in 2012.