Maguire, 33, signed a new one-year contract with the option of an additional year this week as he committed his future to the side under interim boss Michael Carrick.
The England international has had a mixed time with the Red Devils in recent years, often being used as a scapegoat for the club’s lack of success which has seen them not lift the title since 2013.
His new deal represents the trust United have in him and how he has worked his way back into the side to become pivotal to their backline.
Speaking this week, Maguire opened up on his own ability and how United could improve in the upcoming transfer window.
"I still believe, even at my age, I'm arguably one of the best defenders in the world in both boxes," he said. "I don't think that's in question really; that I can be really effective later on in games, whether you're holding on to a lead or trying to chase a game.
“This summer’s going to be a big summer — we’ve got to recruit really well. Obviously there’s a big manager decision as well, but it is about bringing players in.
“We need more players, we need better quality, we need players to come into the starting XI. And then when everything comes together, we’ll see where it is at the start of the season.”
United brought in Matheus Cunha, Bryan Mbeumo, Benjamin Sesko and Senne Lammens for over £200M last summer but will seek to bring in a midfielder to replace Casemiro this summer.
Maguire will feature in a United side who will fight for the Premier League title next season, likely under Carrick who is set to be handed the permanent role.
For now, the world's most expensive defender will be seeking to secure Champions League football for United and the World Cup for England this summer where he is certain to earn a place under manager Thomas Tuchel.