Although it's understood United are yet to table a bid, the Independent's Jack Pitt-Brooke reports the club is in "the early stage of enquiries and discussions about the transfer." Maddison is believed to be a priority purchase for United this summer.
Maddison joined the Foxes from Norwich City for £20 million last summer but is now expected to cost as much as £60 million to prise from King Power Stadium. Manchester City, Liverpool, and Tottenham Hotspur have all tracked Maddison since he was a teenager at Coventry City and could represent United's competition for the English international's signature.
The 22-year-old is set to represent his country at the European Under-21 Championship this summer and was called into his first senior squad in October 2018. Maddison recorded a Premier League-high 100 key passes during an exceptional first season with Leicester.
Executive vice-chairman Ed Woodward and first-team manager Ole Gunnar Solskjaer apparently want to bring in young British players during the close season. Manchester United have apparently given up on their interest in Borussia Dortmund's Jadon Sancho but were reportedly negotiating a deal for Swansea City's speedy winger Daniel James in May.