Renard was involved in discussions with officials over two rejected first-half penalty claims but his side created enough chances to score from open play had they been more accurate in front of goal.
Morocco were expected to be their biggest rivals for second place, behind Spain, and the 63-year-old told FIFA's official website: "The Morocco team is very good; one of the best African squads".
Morocco is in must-win mode if it wants to reach the knockout stage of the tournament.
The decision to throw open the gates of the capital´s 100,000 capacity Azadi Stadium for the landmark 10:30 pm (1800 GMT) live screening comes with Iran topping Group B after its opening game victory against Morocco on Friday.
Their first match, against Spain, ended in a wild 3-3 draw with Cristiano Ronaldo scoring a hat-trick, but while Santos was pleased with some aspects of that game, he expects his team to improve in certain areas.
However, a lapse of concentration early on proved to be their undoing as Cristiano Ronaldo headed home from close-range in the in the fourth minute. Portugal was pinned back for long periods as Morocco attacked in waves without causing any major scares, and they might have extended their lead when Ronaldo played Goncalo Guedes into the box but Munir stood tall and made a one-handed save.
Spain head to Kazan to face Iran still counting the cost of a chaotic run-up to the tournament during which Julen Lopetegui was sensationally sacked just two days before they opened their campaign.
Hello! Welcome to the Live Updates for Portugal Vs Morocco. A second loss for Morocco will all but eliminate them, while a Portugal loss will put them into a must-win scenario against Iran in a few days.
Morocco wasn't almost as fortunate in its opener, conceding a 95th-minute own goal from Aziz Bouhaddouz to suffer a 1-0 loss to Iran.
The goal was followed by end-to-end football as Morocco pushed forward trying to get back level.