Both men said they were concerned about early goals conceded at the tournament so far and cautioned that a similar setback could be fatal to their cause when they meet Egypt in Monday's quarter-final in Benguela.
"I have been concerned about the beginning of the games for us when we have conceded three goals very quickly and it has made it difficult for us to come back after that," said Le Guen at a news conference in the coastal town.
"We must improve on our concentration because we are up against a very strong Egyptian side," Eto'o added at the same news conference.
Cameroon were caught by a goal in the opening minute against Tunisia in their last group game in Lubango and had to twice come from behind to equalise and sneak through on goals scored into the last eight.
Against Zambia they were also down in the first half but came back to win 3-2, while they lost their opening match at the tournament against Gabon after conceding a goal in the first 20 minutes.
"Our first three games were not that good but we have worked on correcting our errors," Le Guen said. "We have worked on better concentration very hard on the training pitch in the last days."
The French-born coach, who masterminded a turnaround for Cameroon in the World Cup preliminaries last year as they went from last to first place in their qualifying group, said he had been pleased with the team's tenacious ability to extricate themselves from precarious situations.
"I'm very satisfied with the fighting spirit and the cohesion has been getting better and better. We can be very hopeful about that as we look ahead to the World Cup," Le Guen said.
