Both teams lost their opening Group A games this month and another defeat for either would severely dent hopes of a two-two finish and qualification for the semi-finals.
"We had to cut short the celebrations to focus on the ASEC fixture," Ahly football director and former star Sayed Abdel Hafeez told the Egyptian media.
"Time will be found later to celebrate our league success.
"There are two more titles in our sights -- the CAF Champions League and the Egypt Cup.
"It is our destiny to try and win every competition we are involved in," added Hafeez.
Ahly have been African champions a record eight times, most recently in 2013 when they defeated South African opponents Orlando Pirates 3-1 over two legs.
ASEC can boast of just one Champions League title, beating Zimbabwean outfit Dynamos 4-2 overall in 1998.
A brace from Ghanaian John Antwi could not prevent Ahly losing 3-2 away to Zesco United of Zambia on matchday 1 this month.
Goal-shy ASEC fell 1-0 at home against Wydad Casablanca of Morocco, who eliminated defending champions TP Mazembe of the Democratic Republic of Congo in a qualifier.
Antwi is the leading Ahly scorer in the competition this season with three goals while only Yannick Zakri has scored twice for ASEC.
Wydad host Zesco Wednesday in a match set to finish around midnight owing to the Muslim holy month of Ramadan, during which eating and drinking is forbidden from dawn to dusk.
Footballers can be excused, but most observe the fast, leading to late kick-offs of CAF matches in Morocco, Algeria, Tunisia and Egypt.
Zesco have been the surprise side of the 2016 competition, winning five of six qualifiers before a Cletus Chama brace helped upset Ahly.
Udoh and his team-mates are in South Africa to face Mamelodi Sundowns Wednesday in the only Group B fixture after Algerian outfit Entente Setif were disqualified over a pitch invasion.
Sundowns won 2-0 at Setif only for the match to be declared "null and void" while Enyimba were surprise 1-0 losers at home to Zamalek of Egypt, who have a matchday 2 bye.