Both Greece and Japan were beaten in their opening Group C matches, by Colombia and Ivory Coast respectively, and now face an uphill task to reach the last 16.
Japan conceded twice in three second-half minutes to lose against Ivory Coast, with each of the African nation's goals stemming from attacks down the left side of Alberto Zaccheroni's team.
However, Salpingidis, who will likely occupy a right-wing berth for Greece in Natal on Thursday, is not reading too much into that.
"I believe football is a sport of mistakes. When a goal is scored, there is a mistake made by the defence," he said.
"Those two goals do not prove this is a weakness in the Japan team. It could happen in the other side of the defence.
"Japan is a very good team and press a lot who run around the pitch for 90 minutes."
Greece were beaten convincingly in their opening game as Colombia moved ahead after just five minutes through Pablo Armero.
Teofilo Gutierrez and James Rodriguez added further goals, but Salpingidis says Greece have put the reversal behind them.
"We are in very good shape and have left behind the loss to Colombia," he added.
"We are working very hard to get ready for the next match. We are getting ready in the best possible way to face a very strong team.
"We respect everybody at the tournament - every player and every team."
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