Tunisians Esperance begin their CAF Champions League title defence away to Guineans Horoya on Friday in a match-up both clubs hoped to avoid.
"Horoya will be hard to beat in west Africa," admitted Esperance coach Moine Chaabani ahead of the matchday 1 clash at the national stadium in Conakry.
The Guineans staged a heroic comeback to beat Libyans Al Nasr 6-2 there last month in the final qualifying round after trailing by three goals from the first leg.
"We were hoping to avoid the defending champions, but the other clubs in the group also have to face them," said France-born Horoya coach Patrice Neveu.
AFP Sport previews the four groups as the 16 survivors from two rounds of qualifying set their sights on the $2.5 million first prize.
Moroccans Wydad Casablanca, South Africans Mamelodi Sundowns and Ivorians ASEC Mimosas are all former champions and Nigerians Lobi Stars will not be pushovers, especially at home.
Wydad, whose title defence last season ended in the quarterfinals, are coached by astute Tunisian veteran Faouzi Benzarti and should defeat 1998 champions ASEC in Rabat.
Sundowns were champions three years ago and are rebuilding after losing three attackers – Percy Tau and Keagan Dolly to Europe and Khama Billiat to domestic rivals Kaizer Chiefs.
The Pretoria outfit disappointed last season, failing to get past the group stage, and the good home form of Lobi in qualifiers suggests they could make a winning start.
Esperance are seeded first and Horoya second in a section completed by South Africans Orlando Pirates, the 1995 champions, and group debutants Zimbabweans Platinum.
While Esperance have won the competition three times, Horoya reached the quarterfinals last season in their best showing.
Horoya club president Antonio Souare has raised the bar for the latest campaign, telling the squad that "our goal this season is to reach the semifinals".
Esperance should finish top, though, leaving Horoya to contest second place with defensively suspect Pirates, who are away to Platinum in Bulawayo.
Democratic Republic of Congo club TP Mazembe are set to top this group, leaving Tunisians Club Africain, Algerians CS Constantine and Egyptians Ismaily to battle for second place.
Mazembe were shock quarterfinals casualties last season, losing to Angolans Primeiro Agosto on away goals after missing two penalties and having two goals disallowed at home.
The five-time champions will miss injured star striker Ben Malango, though, when they host 1969 champions Ismaily in southern Congolese city Lubumbashi.
Club Africain, the 1991 African champions, have home advantage over Constantine, who won three of four qualifiers, drew the other, and kept four clean sheets.
Egyptians Al Ahly, the record eight-time champions, need to up their game at home to V Club of DR Congo after struggling to get past modest Ethiopians Jimma Aba Jifar in a qualifier.
Ahly scraped through 2-1 on aggregate and will miss injured striker Walid Azaro when they meet the Kinshasa-based 2018 CAF Confederation Cup runners-up.
V Club boast the most prolific scorer in CAF club competitions last year, 15-goal Jean-Marc Makusu Mundele.
Tanzanians Simba, back in the group stage after 16 years, will unleash regular scorers Clatous Chama and Meddie Kagere on Algerian visitors Saoura in Dar es Salaam.
(all kick-off times GMT)
1600 Lobi Stars (NGR) v Mamelodi Sundowns (RSA)
1900 Wydad Casablanca (MAR) v ASEC Mimosas (CIV)
1600 Horoya (GUI) v Esperance (TUN, holders)
1900 Club Africain (TUN) v CS Constantine (ALG)
1300 FC Platinum (ZIM) v Orlando Pirates (RSA)
1300 TP Mazembe (COD) v Ismaily (EGY)
1300 Simba SC (TAN) v JS Saoura (ALG)
1900 Al Ahly (EGY) v V Club (COD)