Quincy was named in the 30-man squad for to prepare for the 2010 World Cup in South Africa, and took part in pre-tournament training in France. He was selected as part of the 23-man squad for the tournament. On 5 June, he scored the only goal as Ghana beat Latvia in their last warm-up match at Stadium mk in Milton Keynes, England. Quincy appeared twice in the group stage as Ghana reached the quarterfinals, in which he was an unused substitute as they went out on penalties to Uruguay.