Greek coach Fernando Santos must find replacements for Avraam Papadopoulos, who is out of the tournament with a knee injury, and Sokratis Papastathopoulos who is suspended after being harshly dismissed against Poland in the Group A opener.
The pair anchored a defence that conceded only five goals in qualifying and Santos will likely pair veteran midfielder Costas Katsouranis with 20-year old Kyriakos Papadopoulos who came on for his namesake in the 1-1 draw against the co-hosts.
The Czechs have defensive issues as well but their problems are mostly of their own making after Russia ran riot in a 4-1 victory on Friday, mainly due to glaring mistakes at the back.
Czech coach Michal Bilek might be tempted to move Michal Kadlec back to central defence from the left side and bring in David Limbersky, while defensive midfielder Tomas Hubschman could also start the game to reinforce the rearguard.
Despite their terrible start to the tournament, Czech defender Roman Hubnik said the difficulty they had qualifying for the finals after a play-off with Montenegro will help them deal with the pressure against Greece in Wroclaw.
UNDER PRESSURE
"If we lose our chances are gone," Hubnik said. "The pressure for this game will be higher than the pressure in our [final group] game against Russia."
While defending is a worry, both teams also need to find their scoring touch with Greece having netted just 14 times in 10 qualifying matches, the lowest tally among the finalists.
The Czechs rely on Milan Baros but the Euro 2004 Golden Boot winner has scored just three times in the past two years for his country and looked isolated with little support against Russia.
The Czechs have been boosted by the fact that striker Baros and captain Tomas Rosicky have finally overcome their injury problems but they must still find a way to break down the Greece defence, which they have failed to do in their last four games.
The Czechs, who have not beaten Greece in 30 years since a 2-1 win in a friendly in March 1982, also have extra motivation against the side that beat them in the Euro 2004 semi-finals.
Poland play group favourites Russia in Warsaw's National Stadium in the second Group A game on Tuesday.
