After losing their opening Group F games, both Japan and Croatia desperately need to pick up three points when they meet each other in Nuremberg on Sunday.
Japan led Australia until the closing stages of their game when they conceded three goals and eventually lost 3-1, while Croatia were unfortunate not to take a point after producing a disciplined display in the 1-0 loss to Brazil.
Japan coach Zico has Akira Kaji available after the wing-back recovered from a badly bruised foot, while Mitsuo Ogasawara looks set to come in on the right of a four-man midfield with Hidetoshi Nakata and anchor-man Takashi Fukunishi in the middle and Shunsuke Nakamura on the left.
Nakamura sustained a bruised thigh in the Australia defeat but is expected to play against Croatia as Zico looks to change from a 3-5-2 to a 4-4-2 formation.
The Brazilian said: "It won't be the first time we have gone with 4-4-2. It will give us more balance and Ogasawara can do a good job for us.
"Obviously we are clinging on for survival but as long as we're still in with a chance we will keep fighting."
Croatia coach Zlatko Kranjcar has doubts over Ivica Olic and Niko Kovac going into the game. Striker Olic came on for the final 35 minutes against Brazil and, although he has a thigh strain, is expected to have recovered in time for Sunday's match.
Captain and defensive midfielder Kovac is doubtful after sustaining a rib injury in Tuesday's narrow defeat but, if he fails to make it, Jerko Leko is expected to replace him.
Kranjcar knows how important the game is, saying: "We said before it will be the key game in the group. I saw the game and saw the mistakes Japan made in the last ten minutes (against Australia).
"We're mentally strong and optimistic we can win the next two games and we are preparing everything to make sure we do so."