Following the England international's dominant displays for the Three Lions at the World Cup this summer, the Telegraph report that United boss Jose Mourinho has made the 25-year-old his first-choice transfer target as he seeks to upgrade the Red Devils' defence.
Maguire joined the Foxes for £17.5m from Hull City last year, but his value has surely skyrocketed after his performances in Russia. Even so, Leicester don't want to let another talismanic player leave the King Power Stadium this summer after Riyad Mahrez joined Manchester City earlier in July.
To fend off interest from Man Utd, Leicester will present Maguire with a new contract reported to be in the region of £80,000-a-week.
United could easily match those wages (and surpass them), but transfer deadline day is fast approaching (August 9th) and as things stand, no formal bid has been launched for Maguire.
Man Utd reportedly value Maguire at £50m, but with the Englishman currently on holiday and the transfer window winding down, Leicester are confident that they can hold out for the remaining three weeks and keep their star man.
However, the lure of Old Trafford is difficult to resist, and should Maguire be tempted by a hefty new wage packet and the promise of Champions League football, then the Foxes could have a much tougher task on their hands.
Meanwhile, Mourinho will look for a new striker should Anthony Martial finally demand a move away from the club this summer - though United want the Frenchman to stay and are prepared to activate a clause in his contract that will extend it to the summer of 2020.