Japan, which finished second in Asian Cup Group D, will enter the knockout phase against Bahrain, which finished in first place in Group E after a 1-0 win over Jordan on Thursday.
"We must never go into a game in a way that hands momentum to our opponents," Japan manager Hajime Moriyasu told reporters in Doha.
Japan failed to win its group due to a 2-1 loss to Iraq, which scored two first-half goals.