Ever since leaving Barcelona for Paris Saint-Germain in a record-breaking €222 million deal last summer, speculation has suggested that a 26-year-old forward is destined to return to Spain.
The football star has not played since the end of February due to a foot injury, but scored 19 goals in 20 appearances in Ligue 1.
However, the 26-year-old had suggested that he would not leave PSG this summer, despite persistent rumours.Barca legend Andres Iniesta has admitted that it is hard to see Neymar returning to Camp Nou in the future.
United are prepared to open the bidding at €227m, €5m more than PSG paid to sign Neymar from Barcelona last summer.
Chelsea midfielder N'Golo Kante was named the Best French Player Playing Abroad.
Treble winners Paris St-Germain suffered their first home Ligue 1 defeat in 42 games as they lost to Rennes.More news: Thiem beats Anderson in Madrid semi-finals
"We were inseparable and had enormous understanding", Neymar said.
He failed to fire the Parisians to the latter stages of the Champions League and has missed the final part of the season after suffering a serious injury.
Brazil kick off their bid for a record-extending sixth World Cup on 17 June against Switzerland, with Tite's men also pitted against Costa Rica and Serbia in Group E.
Mbappe was named young player of the year, beating off competition from the Lyon duo of Houssem Aouar and Tanguy Ndombele, and Bordeaux's Brazilian winger Malcom.
That move is set to become permanent this summer for a fee of up to 180 million euros.