The centre-back has been the subject of persistent criticism for his error-strewn displays in recent months and has now lost his place in Erik ten Hag's side.
Despite retaining possession of the armband, Maguire has been consigned to the bench while Raphael Varane and Lisandro Martinez form an effective partnership at the back.
The former Leicester City man has not started in the Premier League since the 4-0 loss to Brentford in August, and Man United have won four in a row in the top flight without Maguire in the first XI.
However, the 29-year-old has not been dropped from the England squad, and The Athletic reports that he will make the first XI for the Three Lions' showdown with Italy.
The report adds that Maguire is "relaxed and confidence" about his standing in the national team, with the defender playing an integral role in England's World Cup 2018 and Euro 2020 campaigns.
Manager Gareth Southgate addressed the media in Milan on Thursday night, during which he expressed his faith in Maguire's abilities, although he has admitted that the situation is not an "ideal" one.
"Clearly, it's not an ideal situation. You want your best players playing regularly so that they're physically in a good place and mentally in a good place," Southgate explained.
"But he is an important player for us. I think it's important to back our best players. He understands that he's at a big club, big transfer fee and captain of the club so I think that's why the spotlight has been on him more.
"He's focused on training well every day and getting himself back in the team. The squad we've picked, there are a fair number of players you could argue we could have left out, but I think we wanted to keep that group together and to keep them involved."
However, the England boss has warned Maguire and others suffering from a lack of action at club level that they will be at risk of missing out on World Cup spots if their playing situation does not improve.
"But also they know that, for some of them, that they need to be playing more regularly because now we're only a few weeks on from pre-season, so, physically, if they've had a few 90 minutes, that's fine. Another seven or eight weeks, that does start to become more complicated," Southgate added.
Maguire has registered seven goals and one assist in 46 appearances for England since making his senior international debut in 2017 and played the full 90 minutes in three of England's four Nations League matches in June.
The Three Lions are still waiting for their first victory in League A Group 3 and have posted just two points from a possible 12, which sees them sit bottom of the rankings and three points behind third-placed Italy.
Defeat at San Siro would therefore confirm England's relegation to League B before they welcome Germany to Wembley Stadium on Monday.