The 21-year-old sparkled for Spurs at centre-back against Sunderland.
The young defender started the season at right-back - again more through chance than anything else - and was this time called upon to cover for the ill Federico Fazio (and Younes Kaboul).
And the simple facts are these: Dier was brilliant for Tottenham as the north London side beat Sunderland 2-1. He didn't make many - if any - mistakes. He was strong and disciplined. The Black Cats' only goal, meanwhile, came after a careless Jan Vertonghen foul, not through any error of Dier's.
As many suspected, then, the 21-year-old looks a much better player in his preferred position at the heart of defence.
And, if he can deputise so well for the likes of Fazio now, how good could Dier be in the years to come?
The future certainly looks promising for Spurs with Dier in defence - and how good would it be for Mauricio Pochettino's side if they could bring a consistent group of young, English talents through at the back?
Danny Rose may have played woefully (from a defensive point of view) so far this season but he has had his moments and is a Tottenham academy graduate. Kyle Walker, meanwhile, is only 24 years of age.
But Dier could be the biggest talent of them all. Based on the early signs, the exciting 21-year-old could very well be the future for Spurs. He just needs to keep doing what he's doing and watch out for the obstacles that are bound to come his way. Small steps...