Madoui guides title-holders Algerians Entente Setif and Garzitto, whose glory came with Democratic Republic of Congo outfit TP Mazembe, steers Sudanese Al Merreikh.
Setif were surprise winners of the marquee African club football competition last year with then 37-year-old Madoui becoming the youngest coach to achieve the feat.
Setif and Merreikh go into the Group B showdown in Algeria level on three points after two rounds of the six-matchday series with both clubs winning and losing.
The defending champions slumped 2-1 at home to USM Alger and won 1-0 away to Mouloudia El Eulma through a stoppage-time own-goal in games against fellow Algerian clubs.
Merreikh kicked off with a 2-0 home victory over Eulma and lost 1-0 away to USM with a late Sudanese equaliser controversially disallowed.
A USM side coached by caretaker Miloud Hamdi top the table on six points, have two matches against struggling Eulma ahead, and are looking good to win the mini-league.
So, the pressure is on Setif and Merreikh, with their back-to-back matches in Algeria and Sudan likely to determine who advances to the semi-finals with USM.
While Madoui and Garzitto naturally want six points, both would probably be satisfied with four from a home win and an away draw.
A concern for Setif are woeful Champions League home results when it comes to group games. The Black Eagles have been victorious just once in seven mini-league matches, against Zimbabweans Dynamos five years ago, drawn four and lost two.
Merreikh are equally dismal when it comes to mini-league away results with a draw and three losses, but the spirited showing against USM will encourage Garzitto.
“Merreikh have been making early exits from the Champions League for far too long," said the 65-year-old.
“We achieved our first goal this year by reaching the group stage after a few scares and our next ambition is a semi-finals place."
What Setif and Merreikh desperately lack are consistent scorers with no player from either side managing more than two goals from qualifying and group games.
France-born El-Hedi Belameiri, whose six goals last season made him joint leading Champions League scorer, has claimed just one in Africa this year.
Another Champions League-winning coach, Mohamed Youssef, takes charge of Egyptians Smouha in the competition for the first time when they host Group A strugglers Mazembe.
Co-favourites with Setif for the 2015 title, the Congolese have failed to score in draws at home to Sudanese Al Hilal and away to Moroccans Moghreb Tetouan.
No goals in 180 minutes is not what club president Moise Katumbi expects from an expensively assembled squad of Congolese, Ghanaian, Malian, Tanzanian and Zambian stars coached by Frenchman Patrice Carteron.
Group debutants Tetouan have fared disappointingly after the mid-year transfer abroad of leading scorer Mouhcine Iajour, surrendering a two-goal lead to lose at Smouha and failing to score when held by Mazembe.
However, a home victory over impressive Hilal by at least two goals and a draw between Smouha and Mazembe would lift the Moroccans from the bottom of the table to the top.
24.7.2015 19H30 Smouha (Egypt) vs TP Mazembe (DR Congo)
26.7.2015 21H30 Moghreb Tetouane (Morocco) vs El Hilal (Sudan)
24.7.2015 20H30 USM Alger (Algeria) vs MC Eulma (Algeria
25.7.2015 21H30 ES Setif (Algeria) vs El Merreikh (Sudan)
*All times are in local time