Garrido's side lead the way in Group B after collecting eight points from their four games so far, but Nkana put themselves back in contention for a semi-final berth with a pulsating 4-3 win over Tunisian giants Etoile Sahel last time out.
And former Villarreal boss Garrido is taking nothing for granted as he prepares to take his team to Kitwe this weekend.
"The Nkana match is going to be a tough one following the last round's results in the Confederation Cup," said the Spaniard.
"Now they will be looking to secure a semi-final place, but I have complete faith in my team's ability to guarantee qualification."
Al Ahly have been boosted by the news that both striker Emad Meteb and midfielder Hossam Ashour are fit for the game after thigh and stomach complaints respectively.
Following their defeat to Nkana, Etoile Sahel will look to bounce back when they entertain newly crowned Ivorian champions Sewe Sport on Sunday.
Sewe are winless in Group B, but know that that victory in Sousse could put them in the driving seat for last-four qualification.
In Group A, meanwhile, runaway leaders Coton Sport of Cameroon host second-placed AC Leopards from the Republic of Congo.
Coton Sport enjoy a five-point lead over their opponents and know that a draw will be enough to see them finish top of the group with a game to spare.
On Sunday, bottom-placed ASEC Mimosas must beat Real Bambako of Mali and hope the pool’s other result goes their way to stand any chance of qualifying for the semi-finals.
