Regular first-team football is usually a pre-requisite for those hoping to remain in their nation's starting XI.
Take Christian Eriksen, for instance. The Manchester United playmaker was included in Denmark's roster for September's Nations League fixtures.
But Lars Knudsen - taking temporary charge after the departure of Kasper Hjulmand - was quick to warn Eriksen that he might not be quite so fortunate next time around.
Having not played a minute in any of Man United's three games so far in 2023/24, Eriksen is in an 'unsustainable' situation at Old Trafford. Continue to warm the bench over the coming months, and even a bonafide Danish legend could pay with his place in the national team set up.
The same fate could yet befall Victor Lindelof.
Eriksen's fellow Scandinavian is another who, if no departure is forthcoming before the end of the summer window, is likely to find himself gathering moss, dust and cobwebs on the sidelines back in Manchester.
Lindelof's absence from the Sweden squad for next month's Nations League meetings with Azerbaijan and Estonia is not, however, punishment for his declining role at Man United.
MORE UNITED STORIES
Instead, it is down to the injury that kept him out of Ten Hag's squad for Saturday's 2-1 defeat by Brighton and Hove Albion.
"(Emil) Forsberg, (Albin) Ekdal, (Robin) Olsen and Lindelof are all out due to injury," head coach Jon Dahl Tomasson tells Fotbollskanalen.
"(Aston Villa goalkeeper Olsen and Lindelof) were so disappointed. They would almost want to kill to be here. It shows what attitude they have.
"Now, I'm curious to see who steps forward instead."
Tomasson opted to keep Lindelof as his captain when taking over the Swedish national team a few months back.
But should another, younger central defender impress in his place next month, the former Blackburn Rovers boss might have a difficult decision to make going forward.
Fortunately, the PS30 million signing from Benfica should not be short of offers.
The Daily Mail reports that Eintracht Frankfurt could offer Lindelof the chance to revive his career in the Bundesliga. Serie A duo Lazio and Fiorentina are interested too, alongside a number of unnamed Saudi Arabian clubs.
The Saudi Pro League transfer window, meanwhile, does not close until October 6th.
Anderlecht unlikely to sign Christian Eriksen Eriksen, in contrast, does not appear to have anywhere near so many suitors.
Belgian giants Anderlecht have been linked. And while CEO Jesper Fredberg admitted that he would relish the chance to bring a footballer of such quality and pedigree to the Jupiler League, Eriksen's sizeable wages could make any deal impossible.
"I myself have never mentioned the name Christian Eriksen, but of course I know Christian. He is a top player who is still contracted for one year at a top club," Fredberg tells Het Nieuwsblad of the 32-year-old, who is due to become a free-agent in 2025.
"At the moment, (signing Eriksen) doesn't seem realistic. If a door suddenly opens, I want to be the first to step in (but) it's not just about what Manchester United is asking for.
"It will also be about the player's salary demands in such a case."