This is a "Wild Mass Guess" entry, where we pull out all the sanity stops on theorizing. The regular entry on this topic is elsewhere. Please see this programme note.
Stavros Garkos used to be a soccer player during his youth
In "Blood Match", Dino's friends, on an attempt ro recover a photograph of Dino's brother from Stavros Garkos, they instead take a photograph of somebody they have no idea who he is. Given how old that photo can be, I believe it might be from Stavros Garkos during his young days and that he liked to play soccer as a child.