A victory for Japan in Amman against a side they thrashed 6-0 back in June would make them the first side to qualify for the finals in Brazil. A draw might also be enough providing Australia and Oman deny each other victory in an earlier match in Sydney.
But instead of basking in the expectant qualification after four wins from their opening five matches in Group B, Zaccheroni cut a nervous figure on Monday.
"This is a massive match for us and of course there is pressure on myself and the players," the Italian told reporters.
"We are carrying the hopes of everyone back home but I can't let the pressure get to the players and it is my job to make sure they are ready."
Adding to the Italian's greying hairs is the absence of key duo Keisuke Honda, who scored a hat-trick against Jordan in June, and flying fullback Yuto Nagatomo for Tuesday's clash.
Manchester United midfielder Shinji Kagawa is expected to shift from his usual left flank berth to cover the absence of central playmaker Honda, who is missing through illness.
"It is a shame we don't have Honda and Nagatomo because they have both made big contributions to the team, but the players who have deputised for them in the past have done well and I expect the same tomorrow," said Zaccheroni.
Despite the thrashing received in Saitama, Jordan are still in the hunt for the second automatic qualifying berth from the five-team pool after stunning Australia 2-1 in September.
The West Asians, who have never qualified for a World Cup, are bottom of the group on five points from five matches, but just one behind Oman, Iraq and Australia, although the Socceroos have played a game less.
"Jordan have picked up points at home and their win against Australia will have given them confidence," Zaccheroni said.
"They will have home support behind them and will be a very different team to the one we faced last time."
Japan warmed up for the pivotal fixture with a rusty 2-1 win over Canada in Doha on Friday which resulted in the Blue Samurai squad members calling for an improved showing to ensure a positive result in Amman.
Even without the important duo of Honda and Nagatomo, the Asian champions should have too much quality for a side they have never lost to.
Jordan, though, have shown greater commitment and organisation in their home fixtures and their hustling frontline should provide a strong test for the sometime suspect Japanese defence.
"It is a massive game for us but we are well prepared and will try to win," Jordan's Iraqi coach Adnan Hamad told reporters.
"Japan might not have Honda available but I saw the Canada game and know the team has strength in depth. The last time we played Japan we were away from home and the players were tired but we are at home now and have our supporters behind us."
- Sports & Recreation
- Keisuke Honda