Ole Gunnar Solskjaer is keen on reinforcing his defence after a disastrous year that saw United finish sixth in the Premier League.
It means that the Red Devils will be plying their trade in the Europa League for the second time in three years.
Executive vice-chairman Ed Woodward has been desperate to bankroll Solskjaer after telling him that he will seek to buy the players the Norwegian has asked for.
The former Cardiff manager has overthrown the transfer policy at the club and instead told United chiefs to snap up young, hungry, British talent.
It has led them to the acquisitions of Aaron Wan-Bissaka and Daniel James – but one man that is proving elusive to sign is Maguire.
Leicester have slapped a huge £90m price-tag on the Englishman, smashing the world-record fee of £75m on Liverpool’s Virgil van Dijk.
Maguire is understood to be desperate for the move for Charlie Adam has told the ex-Hull defender to push through the transfer.
“I think he’s got to force the move,” Adam told talkSPORT.
“Brendan Rodgers is a good manager and he will learn a lot from him, but if this is the next step of his career when he thinks he’s going to develop again…
“Playing for United is totally different, it’s one of the biggest clubs in the world and with the pressure and the hype of having to win every week, it would be a great move for him.
“Not every player wants to do this and he probably won’t want to do it, but this is a last resort.
“He knows this is the biggest move of his career, it’s the next five, six or seven years of his career where he feels he’s going to develop into a top, maybe a world class, centre-half and he wants to do it.
“Leicester have got the right to play hard ball, but the lad gave everything for Leicester and an opportunity like this is very difficult to turn down.
“If the window closes on August 8 and Harry Maguire has not moved to Manchester United, it does not mean he will want to go and train on his own.
“He will be focussed and he will be ready because he’s a top player and he’ll want the best for Leicester.
“But at this time there’s an opportunity for him to force that move and everybody knows this is the best move for Harry Maguire.”