Already struggling with its absentees, Greece was hit by another setback on Sunday ahead of its Euro 2012 game against the Czech Republic when Giorgos Fotakis pulled out of training with a right thigh injury.
Greece will already be missing two key defenders for Tuesday's match in Group A in Wroclaw, southern Poland.
Sokratis Papastathopoulos is suspended and Avraam Papadopoulos is out for the rest of the tournament with a left knee injury.
Team officials said the 30-year-old Fotakis was injured accidentally by a teammate in training, adding that it was too early to tell if the midfielder's injury was serious.
Fotakis was expected to feature in coach Fernando Santos' plans for the Czechs. Midfield anchor Costas Katsouranis is widely tipped to play in defense, just as he did after Papastathopoulos' red card in Friday's 1-1 draw with Poland in the opener.