The Sunday Mirror says United have joined arch-rivals City, Liverpool and Tottenham in the hunt for football's latest wonderkid.
Redmond, 18, is set for a big move after Birmingham failed to get new contract talks going.
Redmond scored seven goals in all competitions and won Birmingham City's Young Player of the Year award.
His good form alerted the big boys but Birmingham put a £12million price tag on Redmond's head.
But a lucrative new deal has not materialised and Blues could now cash in.