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”.