Dimos/Marigno is a defender. He wears the jersey #3. He is based on the Italian player Giampiero Marini. His full name is unknown. While in the manga, one of his teammates call him Dimos, in 3109 Perfect Data, he is named Marigno. It is likely that Dimos could be a separate player, such as can be seen in Captain Tsubasa J: Get In The Tomorrow.
(Source: Captain Tsubasa Wiki)