McCullough is now on the comeback trail and will next month challenge Oscar Larios for the WBC super-bantamweight title, a fight he secured in part by basing himself Las Vegas. If, as expected, hard-hitting Harrison wins inside the distance against Colombian veteran Victor Polo at the Braehead Arena on the outskirts of Glasgow, McCullough believes the 27-year-old Scot should also head to America in search of richer pickings.