Amad left Manchester United scouts pondering if he can take Cristiano Ronaldo's place in the first-team squad.
The on-loan star fired Sunderland to consecutive wins and reacted positively to rumours he could be recalled by Old Trafford boss Erik Ten Hag by bagging his fourth goal in six games.
The £19m Ivorian wing star was watched by a United scout who will file a report to United chiefs on whether Amad is a contender to fill Ronaldo's vacated squad berth.
Amad has found his niche on the right of the Wearside attacking trio and poached the opener from a couple of yards out in the 53rd minute against crumbling Millwall.
The 20-year-old has plenty of tricks and is now finding some end product after a slow start at the Stadium of Light. Tony Mowbray has worked on his positioning and on being more direct.
Mowbray said: "Diallo is on fire at the moment. He scores goals and gets assists. Playing games is the best for every player. Let him play, let him dance with it. Is Amad going to get us 20 goals this season? Will Man United think he can play in their team… who knows?
“But it is about his growth mindset. I’d say: go and watch your clips, see what you can do better, and what goes wrong. I was pleased he was at the back post and knocked it in.
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“Look, Raheem Sterling got six, seven goals a season then started to get 30. A new coach helped him. It is about helping Amad. I can’t help him do stepovers. I can teach him when the ball is here, you be there. You have to teach them positional football. He is clever and bright. Language is a hell of an issue for us but he watches and listens and nods.”
Alex Pritchard was the architect of the first goal after a neat one-two which allowed Ellis Simms to backheel across goal, which Amad pounced on. Pritchard swiftly added a second himself from 15 yards out after skipping across the box and wrong-footing the defence.
Before the game, Diallo appealed to Sunderland fans to amend a racial stereotyping terrace chant which referred to the size of his penis.
He said: “I love your energy and having you sing my name is incredible. But we need to be respectful. Let's change the song, keep the noise and move forward together.”
Sunderland’s third came from Ellis Simms who rounded the keeper to tap home in injury time. Millwall should have been in front in the first half. Keeper Anthony Patterson rolled a pass straight to Zian Fleming on the edge of the box, but the Millwall playmaker fired his shot wide.
Gary Rowett said: “That was disappointing. They caused us problems for a spell but we had the best chances in the first half.”
