While he was capped at youth level by England, Aluko has since pledged his international future to the Super Eagles.
Rosenior told the Hull Daily Mail: "He's fantastic in training. He's only young, even though he looks about 35, he's only 24. I've not played with many better. I've played with the likes of Louis Saha at Fulham and people like that.
"He's right up there with the best I've played with. If he was English, he'd be great for the national team. I think he'd walk into the England squad. That's how good he is."
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