 After playing with the junior youth teams of Panathinaikos, Maragkos made his debut at the professional level with Panathinaikos, on October 31, 2010, in the top-tier Greek Basket League, during the 2010–11 season, at age 16.His first game in the top Greek League came against Ilysiakos, in a game that Panathinaikos won, by a score of 81–62.Maragkos logged 2 minutes of playing time in his debut game.