A place at next year's World Cup in Brazil is at stake for Patrice Evra and Nani, as several United stars join up with their countries on international duty.
Reds left-back Evra is in coach Didier Deschamps' squad for France's two-legged meeting with Ukraine, who finished as runners-up to England in Group H. The tie opens in Kiev on Friday, 15 November and concludes in Paris on Tuesday, 19 November.
Nani led by example when captaining Portugal in the absence of Cristiano Ronaldo last month, his superb left-footed strike putting his country on the way to a 3-0 win over Luxembourg. The result secured a place in the play-offs for the Portuguese, who face Sweden in Lisbon on Friday, with the second leg taking place in Stockholm on Tuesday.
Javier Hernandez played no part in Mexico's 5-1 first-leg win over New Zealand as national coach Miguel Herrera only selected local-based players for the play-off against the All Whites due to the demands of playing at an altitude of 7,000ft in Mexico City.
The plethora of friendlies taking place will see more members of David Moyes' squad in action around the globe. Antonio Valencia is with Ecuador, who qualified for the World Cup last month, for meetings with Argentina in New York on Friday and Honduras in Houston on the following Tuesday.