The Tottenham Hotspur and England star has impressed playing in defence recently and is now determined to make it his specialised position, having previously starred as a defensive midfielder for club and country.
Dier told Sky Sports ahead of England's Nations League game against Denmark: "People are a bit confused on the subject.
"Since I was eight years old, that's where I've played. When I signed for Spurs it was as a centre-back. "Obviously, I had a great season in midfield and during that season the Tottenham team was built in a way which suited me to play in that position, but as time went on it developed into something else."
Dier explained that he is happy to play in different positions for the sake of the team but has explained that he is now focusing on playing as a centre-back.
The 26-year-old player added: "I'm still willing to play anywhere if that means the team are successful and that's what the manager would want, but I just felt, being 26 and relatively young still, it was time to become a specialist in a position. Otherwise, I feel you can let the years pass you by and you can let your career pass you by jumping around.
"I feel like it was the right time to become a specialist in one position, and as I said before, it's a position where I feel I can fulfil my potential to the maximum. It's kind of enough talking about it and just proving it with my performances on the pitch, but I feel very happy with where I'm at and I just want to keep building on that."