Zamalek coach Augusto Inacio has said that Tuesday's game against Libyan side Ahli Tripoli was "very tough."
"Zamalek is under a very busy schedule and had to travel a long road for the game; of course this influenced the performance," the Portuguese tactician said following the goalless draw in Tunisia.
Despite the draw, the Egyptian side moved to the lead of their African Champions League group.
"In games like this one, you must be satisfied for avoiding a loss. But we targeted a victory. I am not happy over the draw but the players are excused because of exhaustion," he added.
Zamalek beat Zimbabwe's Caps United 2-0 in their opening Group B game in Alexandria earlier this month.
They have four points from two games but USM Alger, who have three points, could move back to the summit if they beat Caps United on Wednesday.
