Maguire is still in some discomfort from the ankle ligament damage he sustained on Manchester United duty seven weeks ago but has declared himself ready to go against the Scots in the Euros cross-border clash at Wembley.
“It’s a big game, I’ve done a few sessions now and feel like my fitness is there, so I’m available for the game,” said Maguire.
“I always felt within myself that I would be fit at some part of the group stage. I didn’t know when. We are going well, we are on the right path. Every day I get more confidence and it gets stronger.
“From speaking to players and physios, I’m sure it will be niggling but as long as its stable and the pain is bearable then I’m sure I’ll be fine.
“I think throughout a career in football if you didn’t play through pain you would probably spend more time on the sideline than you would on the football pitch.
“I have done it throughout my career and so has everyone else who plays week in, week out.”
It is a huge boost for Gareth Southgate who did not expect to have one of his key leaders available until next week’s game against the Czech Republic at the earliest.
The England manager must now decide whether to parachute Maguire straight into the starting line-up against the Scots or put him on the bench.
“It’s Gareth’s decision but the bottom line for me is that I want this country to win. I want us to win at all costs, whether I’m in the team or I am not in the team,” said Maguire.
“I was watching at my house on Saturday. We had a barbecue and I was jumping up and down like a crazy person when we scored.
“When I came in I just wanted to speak about the game to people. They’ve had enough of it over the last few days. I chewed Kalvin [Phillips]’s ear off and Ben White because I’ve known them for a while.”
The uncapped 23-year-old will be on the bench at Wembley as back-up act to Jordan Pickford and Sam Johnstone.
“It’s England v Scotland at a major tournament at Wembley and I’m going to be involved with three lions on my chest. It doesn’t get much better than that unless you’re starting,” told The Official England Podcast.
“I don’t know what I’m going to do when the anthems play. I will be belting it out. I might cry, I might smile, I couldn’t tell you.”