Gerets: Chamakh playing for Arsenal place
Gerets also expected Chamakh, who has had little game time with his English Premier League club, to score when they meet Tunisia in their opening Group C match against Tunisia in Libreville, Gabon, on Monday.
"Players who are not regulars with their club sides in Europe will be motivated not only to do well for their country but also to show their capabilities to their [club] coaches," the former Belgian international told a news conference.
"I'm sure they will want to give something extra to show their good qualities to their coaches. In a way they are also playing for their places at club level."
Asked whether selecting players who were struggling to hold down regular places at club sides would impact negatively on Morocco, Gerets said he saw little difference in their capabilities.
"When we started our preparations for the Nations Cup, all the players did the same work and they showed there is not much difference between those who play regularly for their club and those who don't," he said.
"They are all motivated to play for their country."
Chamakh is expected to lead the attack for Morocco and Gerets said he had a regular scoring record for the country: "He is capable of taking the chances against Tunisia."
The Belgian said he was excited about the potential of his team and fortunate to have the luxury of picking from a full-strength squad.
It includes Dutch-born midfielder Oussama Assaidi, who had been injured in recent weeks. Gerets said he had made a full recovery from an Achilles tendon injury.