The 17-year-old has been linked with several Premier League clubs after impressing for Ipswich.
Keane said: “There aren’t many Connor Wickhams around. You have to be careful not to be blasé and say we’ll take seven or eight million for him.
“I have a figure in mind that we’d have to consider.
“Big teams wouldn’t buy him for what he’s doing now. They’d buy him for what he’ll be doing in four or five years time. United had to pay £28million for Rooney when he was 18.”
Keane added: “Can Connor be as good as Wayne? He has the potential.”
