By Kieran King Details of Cristiano Ronaldo’s first Sporting CP contract and Lionel Messi’s initial Barcelona deal have come to light. Ronaldo, 39, started his career in Lisbon and made his first-team debut in August 2002 during a Champions League qualifying game against Inter Milan. He caught the eye in his maiden campaign in the Sporting senior set-up and earned himself a £12million move to Manchester United in August 2003. Messi, 36, joined Barcelona’s youth system from Newell’s Old Boys in 2000 and progressed through the club’s academy before making his senior bow four years later. The Arg…