United's squad are currently on a post-season tour of Malaysia. They lost 1-0 to ASEAN All Stars on Wednesday and face Hong Kong on Friday in another friendly before travelling home.
Post-season tours like this are not ideal for players following an arduous season, but they represent an easy opportunity of a significant cash injection and Man Utd are crying out for income ahead of a season without European football.
United's performances in 2024/25 were shambolic as they finished 15th in the Premier League, while they passed up a chance to qualify for next season's Champions League by losing to Spurs in the Europa League final.
Ruben Amorim's squad have rightly been slammed for their displays this season, but Diallo has been one of their standout performers and he was sorely missed while he was injured.
Still, Diallo 'stuck his middle finger up at Man Utd fans' this week and has now revealed the 'real reason' for this gesture.
It is suggested that the winger was a 'target of serious personal abuse' and retaliated.
This has been confirmed by Diallo on X, who claims he has received "insults" about his "mom" and insisted that he does not "regret what he did".
"I have respect for people but not for the one who insults my mom," Diallo tweeted.
"I shouldn't have reacted like that but I don't regret what I did. We had a great time in Malaysia with good people."
Amorim also spoke on Thursday, admitting he wants Man Utd to "turn the page" as his squad "cannot hide" after their disastrous season.
"We want to give something to the fans, but it's hard in this moment - we just want to turn the page and improve next season," Amorim said.
"We cannot hide that it is really tough in this moment for us not to close the season, but if there is one thing that is really important in this club it is that we need to face our fans in this moment, and we need to give something to our fans around the world."
On his plans for team selection for Friday's friendly, he added: "I will try to divide because I don't want all the young kids all together.
"I will try to mix these things. We want to be competitive. If they are fit, they will play, and we will have the maximum respect for everybody here and for our fans."