Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Mário Rui Silva Duarte (born 27 May 1991 in Sines) is a Portuguese footballer who plays for Gubbio, as left back. Ribeiro was brought up in F.C. Porto's youth system. Still a junior, he made his senior debuts, appearing six times in two separate seasons with the reserves, in the third division. Released by Porto, Ribeiro signed a four-year contract with Associação Naval 1º de Maio in the 2006 summer, making his top division debut on 3 December, playing 25 minutes in a 0 2 away loss against C.D. Aves, and appearing in a further 11 games as the Figueira da Foz club retained its division status.