Almiron has been in exemplary form for Newcastle this season and going into the World Cup break, had scored or assisted in the last five games.
His total goals for the season are eight, compared to one for the whole of the last campaign, and he won the Premier League Player of the Month award for October.
Paraguay have not qualified for the World Cup but are still playing over the break, with a friendly scheduled against Colombia, who are also missing the competition, this weekend.
Almiron has joined with the Paraguay squad for the Colombia match but it appears he will not be taking part in it.
The winger will miss the match against Colombia this weekend due to physical issues, according to Paraguayan broadcaster Unicanal.
Newcastle will be hoping that there is nothing serious in the cause by which Almiron is missing the weekend game.
Almiron has nearly 50 appearances for Paraguay but he will not be adding to that this weekend and Newcastle will be hoping he is fit and healthy when the season starts again.