With Manchester United captain Harry Maguire not fit for the start of the tournament due to an ankle ligament injury, some fans and pundits identified Mings as a potential weak link in Gareth Southgate’s defence.
As it was, the Aston Villa star - alongside John Stones - formed part of a miserly England rearguard that kept successive clean sheets against Croatia and Scotland in Group D in the absence of their most influential centre-back, who then returned against the Czech Republic at Wembley.
Mings, quoted in The Sun, said: "I did have a tough time in the lead-up to the opening game against Croatia.
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"I think I'm a lot more hardened to outside influences now, but my mental health did plummet. And I have no shame in admitting that because there was so many unknowns about me going to that game.
"I was probably the only name on the teamsheet that people thought, 'Not sure about him'. And that was something I had to overcome. When 90-95 per cent of your country are having doubts over you, it's very difficult to stop this intruding on your own thoughts.
"So I did a lot of work on that with my psychologist. It was hard. I didn't really sleep very well before that first game."
American gymnastics star Simone Biles has made headlines at the Tokyo Olympics by pulling out of several events to prioritise her mental health, while England all-rounder Ben Stokes is taking an indefinite break from cricket to safeguard his wellbeing.
Mings, 28, said: "It's just great that we are playing in a time now when you can speak about mental health, and how you are feeling.
"We have seen with Simone Biles you can speak on how you are feeling and hopefully feel supported by many people."
Additional reporting by the Press Association.
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