The winger was one of the standout performers for Manchester since Ruben Amorim's arrival and admitted he was upset when he heard about the Portuguese coach's departure.
"It was a sensitive issue. I was a bit sad because he was the coach who gave me the most visibility and the most opportunities to play for Manchester United," he told Bein Sports.
"I was really sad. I sent him a message to thank him for everything he did for me, both in my life and, above all, in my career. I wished him the best of luck wherever he goes. It was a tough moment for me, but right now I'm fully focused on Ivory Coast and this tournament. I want to finish strong here and try to win this AFCON," he added.
Diallo also admitted he had a great relationship with the former Sporting coach.
"We had a great relationship, almost like father and son. He understood me, gave me a lot of advice, and let me play with freedom. It's a shame, but that's life. You have to adapt, that's football. I wish him all the best in life and at his next club," he concluded.
The 23-year-old winger has played 16 matches for Manchester United this season, scoring two goals and providing two assists. At AFCON, he has already scored three times in four games for Ivory Coast, who face Egypt this Saturday.
