The French midfielder made waves when he stated that he could seek a new challenge, and those rumours were only fuelled when his agent, Mino Raiola, said that he was working towards a move.
Milenkovic, who is under contract in Florence until 2022, made 34 Serie A starts last term and scored three goals for his side.
The same story claims that Manchester United are willing to pay as much as €80m (£71.6m) for the 24-year-old midfielder, but Lazio are holding out for a fee closer to €100m (£89.7m).
And they are determined to keep the France global going into the 2019/20 campaign.
Pogba has had a rocky relationship with Manchester United manager Ole Gunnar Solskjaer and with many United fans this past season.
The heavily inflated market has also played a part in their decision making.
Do you think United should let Lukaku go?
The France worldwide has suggested he would like to find a "new challenge" this summer amid interest from Real Madrid and Juventus.
Additional to his goalscoring, he has astute defensive qualities which have gathered interest from plenty of clubs including Manchester United.
United know all about negotiating with Inter after their exhaustive and unsuccessful pursuit of winger Ivan Perisic in 2017 - a player Jose Mourinho desperately wanted. The 21-year-old Serb presently plies his trade for Fiorentina.
As well as Maguire and Longstaff, United have also been backed to raid Sporting Lisbon for Bruno Fernandes.
However, Real could be ready to test United's resolve with an opening offer.
The pair could be seen on exercise bikes overlooking the main training group, which Luke Shaw left early.
United are now in Perth, Australia on the first leg of their pre-season tour, in which they will square up against Perth Glory and Leeds United.