Promitheas Patras fortified its backcourt with the signing of point guard Vangelis Mantzaris, who is a two-time Turkish Airlines EuroLeague champion. Mantzaris (1.94 meters, 29 years old) arrives from UNICS Kazan, where he averaged 3.9 points, 2.5 assists and only 1.0 turnover over 10 7DAYS EuroCup games this season. He started in seven of those games in what was his first stint outside of his native Greece. Before joining UNICS, Mantzaris had played eight consecutive seasons for Olympiacos Piraeus, which he helped reach four championship games in the EuroLeague and lift the trophy in 2012 and 2013. He also took Greek League titles in 2012, 2015 and 2016, and won the Intercontinental Cup title in 2013. In 210 EuroLeague career EuroLeague games with Olympiacos, Mantzaris accumulated 912 points (4.3 ppg.) and 447 assists (2.1 apg.).
Mantzaris started his career with Peristeri GS Athens. He has also been a member of the Greek national team and was quite successful at the youth level. Mantaris helped Greece win gold medals at the 2008 U18 European Championships and the 2009 U20 European Championships, as well as silver medals at the 2009 U19 World Championships and the 2010 U20 European Championships. Promitheas will compete in the EuroCup Top 16 in Group F with Umana Reyer Venice, Germani Leonessa Brescia and EWE Baskets Oldenburg.