Reports in the Japanese media on Wednesday claimed the Bosnian, who led Algeria to the Round of 16 at the 2014 World Cup in Brazil, would be sacked if Japan are defeated by the Asian champions at Saitama Stadium on August 31.
A victory would mean that Japan, who lead Group B in Asia's qualifying tournament, would seal their place at the World Cup finals in Russia.
However, defeat against Australia and Saudi Arabia, who they meet on September 5, would leave the team facing a series of playoffs to progress.
"All the talk right now is positive," JFA technical director Akira Nishino was reported as saying by Kyodo News.
"We don't discuss speculations or ifs and buts, and the issue was not raised today. We just want to get it done at home against Australia and that's it."
Japan were held to a 1-1 draw by Iraq in their previous qualifying match in June. But Nishino insisted that the association was fully supportive of the team's efforts.
"We - from the president to me to the technical committee - have always maintained that we will be fully behind this team during the World Cup qualifying, and that hasn't changed," he said.
Japan, who are aiming to qualify for a sixth straight World Cup after making their debut in France in 1998, have not beaten the Socceroos in qualifying for the tournament since Australia joined the Asian Football Confederation in 2006.
(Reporting by Michael Church; Editing by Christian Radnedge)
