As things stand, the reigning Africa champions currently occupy sit second in Group A but a win this afternoon will guarantee a spot in the quarter-finals.
The Red Devils claimed a convincing 3-0 win over Al Merreikh in their opening group game in February, but Mosimane wants his players to show a lot of effort.
"Rather, it will be a reality if each player makes the utmost effort during the encounter, which will be an offensive one by the two teams as both of them eye the victory.
"Al Ahly's clash with Al Merrikh will be difficult, as each team in the group before this round will have two games of six points remaining that will definitively determine the two teams who qualify for the next round.
"Both teams are looking for victory in tomorrow's match. Al Ahly wants to return to Egypt with the three points of the match, to take an important step towards leading the group.
"Injuries are part of football. No one denies the importance of Ali Maaloul and Hamdi Fathi, but big teams like Al Ahly are able to deal with all situations and has alternatives in various positions," he added.
