Rohr will not underestimate the challenge ahead for the Super Eagles.
Having only scraped through the group stage, Baxter's side shocked tournament hosts Egypt in the last 16.
"We have to keep fighting, and against South Africa, we have to adapt to their pace".
Rohr was positive about the veteran midfielder's progress, saying: "Mikel is trying to run already, so we will see if he could be fit one time for [South Africa] clash".
However, in a rebuttal Bafana Head Coach Stuart Baxter returned the compliment with a slight dig, " I don't think he's fooling anybody", he said in his presser.
Team News: Who is available, injured or suspended?
Nigeria boss Rohr highlighted his side's defensive vulnerabilities prior to the clash against South Africa, but Premier League star Ndidi has backed Akpeyi to prove his critics wrong as the Super Eagles continue their mission to secure a fourth Afcon title. Can they spring an another upset this evening against the Super Eagles?
South Africa did not have a good start to the campaign, losing to the Ivory Coast and Morocco by a lone goal each.
Due to Nigeria's loss to Madagascar, the team have earned R460 000 so far, R141 000 for each of group stage wins plus another R177 000 for reaching the last 16 and R212 000 for qualifying for the quarter-finals. "The loss to them in the qualifiers was tough, but this is a tournament quarter-final match and it will be a different matter".
"One of the important things for us is to remain very, very humble", he said.
"Of course, they under-estimated us and I understand them".
Nigeria has only won the Cup of Nations on two occasions. They look the most unsafe players for Bafana Bafana going forward and they have been instrumental, especially in the last game.
Senegal, who beat Benin 1-0 earlier on Wednesday, play either Madagascar or Tunisia in the other semi-final.
Idrissa Gueye scores the victor for Senegal against Benin.