Japan are hoping to sharpen their skills before the 2010 World Cup by tackling Cristiano Ronaldo's Portugal away in a friendly in March.
The Japan Football Association (JFA) said on Friday they had begun talks with Portugal about the possibility of playing on March 3.
If they agree on the date, Japan would have to rearrange their Asian Cup qualifier against Bahrain, which was also scheduled for March 3.
JFA officials have pledged to leave no stone unturned as they bid to win their first World Cup finals match on foreign soil in South Africa next year.
Japan have drawn two European opponents in their World Cup group while Portugal are in the same pool as Japan's Asian neighbours North Korea.