Otto Rehhagel believes that his players need to follow his instructions once again or Greece will be heading home from the World Cup at the earliest opportunity.
The German coach's success in leading Greece to an entirely unforeseen triumph at the 2004 European Championship was based upon the players following his tactics precisely, denying opponents space and capitalizing on set-piece attacks.
They failed to stick to his defensive plans in their opening match against South Korea and conceded a crucial early goal when they failed to cut out a free kick.
South Korea eventually won 2-0, and Rehhagel knows Argentina and Nigeria could punish Greece even more in the remaining Group B matches.
"We've got to analyze the match in a very sober manner and very factual manner and learn our lessons," Rehhagel said. "We're heading up against the harder teams now and, if we were unfocused like this, we are already giving up a goal to our opponents."
Rehhagel had said before the game at Nelson Mandela Bay Stadium match that his players were like schoolchildren who needed a teacher to give them double homework on subjects they were failing.
If he is true to his word, the Greek players will be practicing their shooting and defensive drills for hours at their Durban base in the buildup to Thursday's game against Nigeria in Bloemfontein.
Vassilis Torosidis blazed a third-minute shot over the bar from a corner and, four minutes later, he and his fellow defenders failed to mark Lee Jung-soo at a free kick, allowing the Korean to tap into an unguarded net.
The kick could even have been cleared before it reached Lee but Konstantinos Katsouranis seemed to mistime his leap and the ball brushed the top of his head as it sailed across the area.
"You've got 18 people in the penalty area and there is a hard-hit cross, anything can happen if the defender doesn't head away the ball properly," Rehhagel said. "We really have to get our act together.
"We've got to improve a couple of things and be brave and courageous enough."
Rehhagel also needs to decide whether to retain midfielder Giorgos Karagounis after substituting his captain at halftime. Karagounis was part of the triumphant 2004 side but looked cumbersome against the mobile South Korean midfield.
"Karagounis never got the hang of the play," Rehhagel said. "He was never agile enough and it didn't work out for him. I always act swiftly when I see a change is required. It's my job to do that as a coach."
Fanis Gekas was one of the few Greek players to perform well, holding up the ball and forcing two late chances. One hit a Korean defender and the other was punched over the bar by goalkeeper Jung Sung-ryong.
"We have five days to prepare for the next match," Gekas said. "We have to correct our mistakes, then we'll see."
Gekas is likely to keep his place in attack but Rehhagel may need to sacrifice one of the other two strikers after Greece was outnumbered in midfield by South Korea.
But it could be difficult for Rehhagel to strike the right balance between defense and attack.
Greece failed to score at its only previous World Cup, losing all three matches, and needs to find some goals to have any hope of advancing to the next round.
"We have very few options," midfielder Alexandros Tziolis said. "There's no other option than to go all out."
