Ghana's Anthony Annan believes mental preparation will be the key to success in next month's Group I clash in Sudan.
The two teams both boast 13 points in the group, but the Black Stars lead on goal difference.
"We have to work very hard before we can achieve something in Sudan, because it's going to be very difficult," the midfielder told BBC Sport.
"We have to be mentally prepared and put everything in place before we can beat them."
With the Confederation of African Football electing that teams sharing a similar a number of points go through on the head-to-head record, Ghana need just a draw in Sudan to qualify.
The two teams drew in Accra earlier in the campaign, but the Black Stars will emerge above the Sudanese on 07-09 October should they draw as they will lead overall on goal difference in the group.
"They have improved a lot because we now have the same points as them and only lead on goal difference," explained Annan, who is currently playing for Dutch side Vitesse Arnhem.
"It's going to be difficult in Sudan because the temperature and everything else is a little bit difficult.
"We have to approach this game very seriously - and we have to be on our form."
Annan was speaking after Monday night's 1-0 defeat to five-time world champions Brazil in an international friendly in London.
Leandro Damiao's first-half strike secured the points after Ghana were reduced to ten men following Daniel Opare's dismissal for two yellow cards just after the halfhour.
However, Ghana kept the scoreline to a minimum thanks to two wonderful late saves from goalkeeper Adam Kwarasey.
The man who recently deposed long-time number one Richard Kingson superbly stopped Alexandre Pato's late header before stopping a Ronaldinho free-kick in the dying moments.
"I thought Pato's header was going in until he made that fantastic save," Annan added.
"Then came the save from Ronaldinho's free-kick and we are very pleased with him that we didn't concede more goals because of his saves.
"If he keeps playing like he did [against Brazil], he is going to be a very good goalkeeper."
Kwarasey, 23, made his Ghana debut in Friday's 2-0 win over Swaziland, a result that kept the 2010 World Cup quarter-finalists top of Group I - just ahead of Sudan, who won 1-0 in Congo-Brazzaville.