Tottenham defender Eric Dier has questioned the "unfair" criticism he has received since shifting to centre-back but accepts he can still improve in that position.

The England international, formerly deployed in holding midfield, was dropped towards the end of Jose Mourinho's tenure for what the ex-Spurs boss put down to "a lack of confidence" following some high-profile errors.

Dier returned to the side for Mourinho's final two games in charge, however, and has retained his place in the heart of defence for interim manager Ryan Mason's first three games, including the EFL Cup final loss to Manchester City.

He impressed in Sunday's 4-0 win over Sheffield United by making more clearances (five) than any player on the field, while he was involved in four times as many aerial duels (eight) as any other Spurs player, 75 per cent of which he won.

After looking more commanding since being recalled to the starting line-up, Dier feels that he has been harshly judged in the past.

Asked if Tottenham fans have seen the best of him since moving into a deeper position, Dier said: "I think they've seen it in periods. I've got mixed emotions towards it really. 

"At times, I feel like it's a bit unfair and a bit – I'm trying to think of the right words – sometimes I've made a mistake or something has led to a goal and one mistake is talked about like it's four or five.

"I've felt that at times. As defenders, you're always going to make mistakes at times and the most important thing is how you react to them."

While Dier has not made any errors that directly resulted in a goal this term, he has conceded two penalties in the Premier League, the joint-most in the division.

This is likely partly to blame for criticism of Dier, though he has also proven himself ready to put his body on the line for Spurs.

Dier has made an average of 1.1 blocks per 90 minutes in the Premier League this term, with only Japhet Tanganga averaging more among Tottenham players – but he has only featured four times.

The 27-year-old's tackle-success rate of 65 per cent is similarly high in the context of the Spurs squad, with Moussa Sissoko (72.7 per cent) and Giovani Lo Celso (81.8 per cent) the only individuals to have made more than four appearances to post a better record.

"I'm really happy to have played the last few matches. I've felt good in those games. I want to be playing, I want to be performing to a level I know I can," Dier added.

"I think I had a very good first six months and it dropped a little bit for a few games, but I feel like I've been back to a good place for a couple of months now.

"I believe I can still perform to a much higher level. I'm happy to be playing, obviously, and I've just got to keep working hard and improving."