Amorim insisted in the latter stages of his time as Sporting manager that he would not be raiding his former club in January, but he refused to rule out incomings from the Green and Whites next summer.
Viktor Gyokeres and Geovany Quenda are currently being heavily linked with moves to Old Trafford, but there have also been claims of firm interest from the Red Devils in central defender Diomande.
According to Sky Sport Switzerland, Amorim has spoken with Diomande about a potential move to Manchester, with the new Red Devils head coach desperate not to miss out on his signature.
Manchester City are also believed to view Diomande as a 'priority', with Man United therefore potentially needing to move quickly if they are to win the race for him ahead of their Manchester rivals.
Amorim 'has discussed Man United move' with Diomande'
The 20-year-old has made 14 appearances for Sporting during the 2024-25 campaign, while he has represented the club on 69 occasions in all competitions since arriving from FC Midtjylland in January 2023.
Sporting are in a strong position when it comes to the defender's future, as his contract is due to run until June 2027, but the deal does have a release clause of €80m (£66.7m).
"I won't [sign Sporting players] in January, that's what I said. I don't know about the summer," Amorim said before his arrival at Man United, with the English outfit being linked with mid-season moves for a number of Sporting stars.
"The first point is to hold on until the summer. Sporting players are very good players, I don't know, we'll see. I know the phenomenon of football especially in England, and I know how things change."
A move for Gyokeres in January would be impossible due to the numbers involved, but it has been claimed that Man United are looking to wrap up a deal for teenager Quenda at the start of 2025.
Do Man United need another centre-back?
Leny Yoro is closing in on his debut for Man United, with the centre-back recovering from the fractured metatarsal that he suffered during pre-season, and the Frenchman is viewed as a generational talent.
Matthijs de Ligt and Lisandro Martinez are also expected to be starters this season in Amorim's 3-4-3 formation, but Jonny Evans, Victor Lindelof and Harry Maguire are all out of contract next summer.
Evans and Lindelof are both expected to leave, and even if Maguire has his deal extended, there will be space in the squad for a new central defender, with Diomande seemingly Amorim's leading defensive target for next summer.