El Kaabi starred at the 2018 tournament, scoring nine goals in six matches for the host nation as they won the competition restricted to home-based players for the first time.
The same year, Benhalib was the leading scorer with 12 goals in the CAF Confederation Cup, the African equivalent of the UEFA Europa League.
The predatory instincts of El Kaabi won him a contract with Chinese Super League outfit Hebei China Fortune, who loaned him to Wydad Casablanca this year.
Benhalib plays for Raja Casablanca, three-time African champions and arch rivals of Wydad, with whom they share the biggest stadium by capacity in the north African kingdom.
Wydad and Raja stars dominate the squad chosen by coach Houcine Ammouta to face Algeria in Blida, 55 kilometres (34 miles) southwest of Algiers.
In the absence of El Kaabi and Benhalib, one of the biggest threats to Algeria could come from an unusual source.
Mohamed Nahiri is a Wydad full-back, but he scored five goals in the CAF Champions League last season and another last weekend in their first outing of the latest edition.
Algeria are not able to call on any of the players who won the Africa Cup of Nations in July, but they have selected Zakaria Benchaa and Amir Sayoud, who have shown impressive early season form in the two African club competitions.
Benchaa bagged a brace last Sunday for USM Alger, the second time he has achieved the feat in three Champions League outings.
Sayoud has netted once in each of three matches played by CR Belouizdad in the Confederation Cup.
A worrying statistic for Morocco is that the last three Nations Championship winners to defend the title -- Tunisia, Libya and the Democratic Republic of Congo -- all failed to qualify.
Tunisia host Libya on Saturday in a geographically-based qualifying competition so only two teams from the north of the continent can make it to the 2020 tournament in Cameroon.
Nigeria, who reached the 2018 final only to have Peter Moses sent off and suffer a 4-0 hiding from Morocco in Casablanca, are away to Togo, who edged past Benin in the previous round.
Ghana have home advantage first as they seek to avenge a shock 4-3 aggregate defeat by Burkina Faso in 2018 qualifying.
DR Congo, the only country to win the Nations Championship twice, visit the Central African Republic as they chase a fifth appearance at the tournament, which now features 16 teams.
After surprising Kenya, Tanzania host Sudan hoping history repeats itself as they won home and away when the countries last clashed.
In the southern region, eSwatini (formerly Swaziland), Madagascar and Lesotho are hoping to secure finals places for the first time.
eSwatini and Madagascar play at home against Zambia and Namibia respectively while Lesotho visit Zimbabwe, whose Prince Dube scored a hat-trick in their last outing, against Mauritius.