The 25-year-old defender showed his versatility - one of the attributes which has impressed Redknapp - with a solid display at left-back for Belgium in Saturday's 1-0 friendly defeat against England at Wembley.
Quoted in The Sun on Sunday, the Spurs boss said: "Jan is a terrific passer and versatile too. He can play at the heart of defence but also plays very comfortable at left-back.
"I hope a deal is done but I don't think it's quite finished yet."
The player revealed on Friday night he was close to joining the north London club, claiming a deal could be done in the next "couple of weeks or maybe days".