Mbeumo will lead the line for Cameroon, Amad will feature for Ivory Coast, while Mazraoui is a key player for Morocco ahead of the Africa Cup of Nations tournament.
Tournament regulations mean United should release the trio two weeks before the respective first games of Cameroon, Ivory Coast and Morocco.
That would mean letting them leave around the Premier League encounter with Wolves at Molineux on 8 December.
United management, however, want to delay their departure until December 15 and after their clash with Bournemouth.
"We have the rules for when we have to release the players - we are trying to have the players a bit longer," said United manager Ruben Amorim on Friday.
"It is not just in our hands. We will see. We will try to arrange something with the federations."