Maguire has been out of action since suffering ankle ligament damage playing for Manchester United in their Premier League win at Aston Villa on May 9.
The 28-year-old missed United’s defeat to Villarreal in the Europa League final last week, but was still named in the England squad for the European Championship.
England manager Gareth Southgate admitted it will be a “tight” call on whether Maguire can be involved in the Three Lions’ group opener against Croatia on June 13.
“The fear that I had was missing everything. I knew it was quite a bad injury,” Maguire told newspaper The Sun.
“I would jump out of bed and put weight on my ankle, which I probably should not have done, and test it to see if the pain was still there. Every morning I woke up wishing the pain would be gone. Unfortunately, it was not to be.
“Ahead of the (Europa League) final, I could still not run on the ankle. But it is now improving and getting better, so I am just looking forward to the Euros.
“I generally try to play through injuries. I know it was not the impact of the challenge at Villa that caused it. It was more of a twist, so when I did that, I knew it would be some sort of ligament damage. And obviously it was really bad timing for myself.
“To play so many games on the spin and not get many injuries, but to then miss the Europa League final and the end of the season for Manchester United, was disappointing for the club and myself.
“I have not picked up many knocks. You have freak tackles, people falling on you, you twist things, but I have avoided muscle injuries. But I am looking forward to getting back as soon as possible.”