Whitthread won the 1980 British Junior (under 16) snooker championship. At 14, he was one of a group of players known as the "Magnificent Seven" managed by Henry West, the others being Patsy Fagan, John Virgo, Joe Johnson, Tony Knowles, Tony Meo, and Jimmy White. Aged 15, he recorded a 3–1 win over 1979 World Champion Terry Griffiths at the Warners Holidays tournament in 1980. Whitthread was regarded as an outstanding prospect, but did not achieve the level of success that was predicted.