The 1995 champions suffered a humiliating first round defeat two years ago after underestimating Gaborone United from neighbouring Botswana, losing a two-goal advantage at home and the tie on away goals.
Libolo have limited international experience and none of their players made the squad for the just completed Africa Cup of Nations in Gabon and Equatorial Guinea, but Angolan club football standards are higher than those of Botswana.
Soweto-based Pirates turned 75 this year and club chairman Irvin Khoza craves a second CAF title after shocking ASEC Mimosas 1-0 in Ivory Coast to capture the 1995 title.
He invested heavily in new players last month, including former Arsenal and West Ham striker Luis Boa Morte, but they missed the CAF registration deadline and can play him only if the Buccaneers reach the mini-league phase.
To get there Pirates must eliminate Libolo, Sunshine Stars of Nigeria, and one side from Revenue Authority of Uganda, Correctional Services of Lesotho or Djoliba of Mali with the latter the most likely opponents.
It is a difficult path to the eight-club group phase although superstitious Pirates supporters happily recall that the club overcame Nigerian opponents BCC Lions in the second round 17 years ago.
Pirates returned to action in midweek after a two-month mid-season break and beat Black Leopards 1-0 with rust evident in many of the players although Libolo are similarly handicapped with the Angolan championship yet to kick off.
Brazil-born coach Julio Leal is pinning a lot of faith in veteran striker Benni McCarthy, who wants to complete a unique double after winning the UEFA Champions League with Portuguese club Porto.
"Benni is a footballer of superior quality who brings an extra dimension to the team. His strengths include holding up the ball, bringing team-mates into play and an ability to score goals," boasted the South American.
Vita Club of the Democratic Republic of Congo and Zamalek of Egypt are other former champions in action this weekend with a further six led by title holders Esperance of Tunisia receiving byes.
Although the Kinshasa outfit have disappointed in recent appearances, they will are favoured to establish a winning lead at home to Athletico Olympic of Burundi.
Zamalek, whose record of five Champions League titles is bettered only by Cairo neighbours Al Ahly with one more, face a tougher challenge away to experienced international campaigners Young Africans of Tanzania.
Tusker of Kenya host APR of Rwanda in an east African derby and the return of Power Dynamos of Zambia after an 11-year absence begins with a game in Madagascar against debutants Japan Actuel.
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