Rafa Benitez will have a keen eye on events on the pitch in Algiers and Bangkok.
The first games of the international fortnight kick off today.
On-loan striker Islam Slimani, yet to kick a ball for the club, is in the Algeria squad for a game against Tanzania in Algiers.
And goalkeeper Martin Dubravka, signed on loan from Sparta Prague, will play for Slovakia against the United Arab Emirates in Bangkok.
United manager Benitez left Slimani out of Sunday's friendly against Royal Antwerp in Spain.
However, Slimani – who has been recovering from a thigh injury – could yet play for his country.
"What we have to do and what we want to do is be sure that he's fit," said Benitez. "And if he can play with the national team a little bit, that is a risk, because he's not playing for us.
"But if they decide to play him, it is because he will be fit.
"Hopefully, he won't have any problems. It is something we know we cannot control. If he's fine, it means he will have more chances to compete against the others."
Dubravka, meanwhile, was looking forward to linking up with his international team-mates, but not the 10-hour flight to Thailand.
The 29-year-old said: "I'm really looking forward to playing for the national team again – but it's a long way to Thailand!
"I don't like to travel for 10 hours on a plane, but I'm really looking forward to playing again with the national team. We're like a family, that's why we were successful in the few games before I came to England.
"I'm very much looking forward to that."
Asked about the international break, Benitez said: "It's the worst thing for us, because you have to keep an eye all the time, checking everyone, and then after every game if they are fine or played or didn't play."
Newcastle, 13th in the Premier League, take on Huddersfield Town at st James's Park on March 31.