 Millington spent the next 18 months in the reserves before he was transferred to Crystal Palace in October 1964.After two seasons at Selhurst Park, Millington was sold to Peterborough United in March 1966 along with Derek Kevan for a combined fee of £15,000.At Peterborough, he replaced Willie Duff, making his debut on 1 October 1966 in a 5–2 defeat at Brighton & Hove Albion.