Egypt and Nigeria have already claimed two of the five African slots for the tournament in Russia and the final set of qualifiers being played over the next week will determine the other three.
Senegal could be the first through on Friday if they win away against South Africa to guarantee top spot in Group D.
The match in Polokwane is a replay of last year's 2-1 win for South Africa at the same venue, which FIFA later found had its outcome manipulated by the Ghanaian referee Joseph Lamptey, who has since been handed a life ban.
It means Senegal and South Africa play each other twice in the space of four days with a return encounter next Tuesday in Dakar.
Senegal, who need two points to secure a World Cup berth, have been boosted by Sadio Mane's recovery from a hamstring injury suffered in their last qualifier in October.
"I'm happy to be back, because it was not easy to recover. I was hurt, but I worked hard to return. I'm ready," the Liverpool player told reporters.
SNATCH TOP PLACE
Bottom placed South Africa could yet come from behind and snatch top place if they win both matches.
However, their preparations have been hampered by injury to goalkeeper Itumeleng Khune and the decision of Dutch-based midfielder Thulani Serero not to travel because he was not guaranteed a starting berth.
A solitary point at home for Tunisia on Saturday, when they host bottom placed Libya, will see them qualify for the finals for the first time since 2006, finishing ahead of the Democratic Republic of Congo in Group A.
Group C will also be settled on Saturday where Morocco lead the standings by a single point from the Ivorians, who have been to the last three World Cups but have been struggling in recent times without the influence of Didier Drogba and Yaya Toure.
Anything other than a win for the Ivorians will give Morocco their first appearance at a World Cup in 20 years.
"It's like a cup final we have to win," said Ivory Coast coach Marc Wilmots at a news conference on Wednesday.
(Editing by Christian Radnedge)
