The Asian giants were denied two points by Aleksandr Kerzhakov's equalizer for Russia while the North Africans fell victim to a late Belgium comeback in Belo Horizonte.
Both teams lost points from winning positions in their first matches. Algeria was undone by two second-half Belgian goals after a 25th-minute penalty from Sofiane Feghouli had given it a shock lead over the group favorite, while Aleksandr Kerzhakov rescued a point for Russia against South Korea.
Algeria's defensive approach invited Belgium to complete its comeback in the last 20 minutes at Mineirao, something coach Vahid Halilhodzic knows his team cannot afford to replicate in Porto Alegre if it wants to make a serious qualification push.
"I feel very disappointed. We missed it. We could have won. My players allowed Belgium to hold and use the ball for too long without chasing and breaking," he said after the match.
Now it is expected to show some of the attacking prowess it exhibited in the CAF qualifiers, with goal scorer Islam Slimani an option in attack, although El Harbi Soudani should retain his spot. Whichever man Halihodzic goes with, Algeria will be expected to benefit from Sofiane Feghouli's skill and creativity in midfield.
The South Korean side, for its part, will also be determined to get a better result Sunday, with coach Hong Myung-bo praising the Warriors' performance against Russia last time around, despite suffering a late equalizer in a fairly even match.
"I want to thank to my players, who did their best until the last minute," the coach said. "I think it worked well. The condition of the players and the organization of the team was good."
No big changes should be made from the 4-4-2 that almost secured victory over the Russians a few days ago, with attacking starters Heung-Min Son and Chu-Young Park expected to do better in southern Brazil.