According to Tuttoatalanta, Man United Scouts sent to view Edererson, and Retegui, both 25, in their 1-0 Serie A victory on AC Milan on Sunday.
United is said to have contact with both players' representatives, while Ruben Amorim is preparing for a large rebuild this summer.
Both players were staring at Atalanta this season, in which Edererson settled as one of the best defensive midfielder in the Serie A, while Retegui has scored 26 goals in 44 games in all competitions.
Amorim's side is expected to have a busy summer with different players who are signed and more and more to be sold.