The north Africans drew their opening game with Croatia 0-0 and victory over Belgium would put them on the brink of reaching the knockout stage for the first time since 1986.
Morocco have four players in their squad who were born in Belgium including Selim Amallah, who started against Croatia and plays his club football for Standard Liege.
Bilal El Khannouss and Anass Zaroury, who both played for Belgium's youth teams, and Ilias Chair were also born in the European country.
"They have a special emotion and a positive energy and you have to try and draw from that," Regragui said at his pre-match press conference on Saturday.
"It's a special match for them and we all know that.
"But what we have to do is try and put that into context.... I almost brought one of those players into the press conference and then I realised I shouldn't do that as it would put pressure on them."
Fourteen of Morocco's 26-man squad were born outside the country, including star players Hakim Ziyech and Achraf Hakimi, who were born in the Netherlands and Spain.
"You need to represent the country that you feel," said Belgium coach Martinez, speaking in his press conference.
"At club level you play for different reasons. Sometimes it's a coach, sometimes it's a project, sometimes it's a challenge, sometimes it's where you are in your career.
"When you play for your national team it comes from the heart."
Morocco are sweating on the fitness of full-backs Hakimi and Noussair Mazraoui but Regragui said they could both be ready to start at the Al Thumama Stadium.
"We must decide whether we take the risk to start them, but we will see tomorrow," he said.
Belgium kicked off their World Cup campaign with a 1-0 win over Canada, despite being outplayed for long periods, in what looks a wide-open Group F.
"We're in the group of death," said Regragui. "Everyone thought Canada would be an easy team but we can see now that won't be the case.
"It's the group of death and we want to get out of it."
Belgium are still ranked second in the world but many of their "golden generation" of players are in their 30s and they struggled with the pace of a young Canada side.
However, Regragui was keen to insist that his team were going into the game as underdogs.
"Belgium are the favourites," he said. "They have an excellent coach. They have excellent players.
"(Kevin) De Bruyne, (Eden) Hazard, (Axel) Witsel. They have great players on the bench -- (Romelu) Lukaku or (Michy) Batshuayi. Let's call a spade a spade, they're the favourites."
Check the 2022 World Cup schedule and groups standings.
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