Lionel Messi is yet to play for Paris Saint-Germain this season but has been called up to Argentina's squad for their World Cup qualifiers next month.
Having led Argentina to Copa America glory, Messi made the shock switch from Barcelona to Paris earlier in August, though he is yet to make his debut for Mauricio Pochettino's team.
The 34-year-old, along with fellow former Barca star Neymar, is expected to make his bow against Reims in PSG's final game before the international break.
Messi, along with club-mates Angel Di Maria and Leandro Paredes, would then travel to South America for matches against Venezuela, Brazil and Bolivia.
However, despite Pochettino having given his blessing for Messi to play for his country next month, this could result in the trio missing up to four of PSG's September fixtures.
Argentina and Brazil are both on the French government's 'red list' for travellers, meaning arrivals must quarantine for 10 days once they return to France unless they have been fully vaccinated.
It is unknown if the players in question have yet received both doses.
PSG face Clermont on the second weekend in September, with a tussle against Lyon following a week later.
A 10-day quarantine period would mean Messi and team-mates would certainly miss those matches, as well as the opening round of the Champions League group stage, which is to be played on September 14 and 15, while an away trip to Metz in Ligue 1 could also come too soon.
Travel restrictions could well change in the coming weeks, though PSG will not be the only team fretting over possible mandatory quarantine for players in Lionel Scaloni's squad.
Premier League players Emiliano Martinez and Emiliano Buendia, both of Aston Villa, and Cristian Romero of Tottenham would have to isolate regardless of their vaccination status under the current travel restrictions imposed by the UK government.
Meanwhile, Juventus forward Paulo Dybala has earned a recall after almost two years out of the picture.
Dybala, who endured an injury-hit 2020-21 but scored in Juve's 2-2 draw with Udinese on Sunday, last featured for Argentina in November 2019.
With Sergio Aguero and Mauro Icardi both unavailable due to injury, and Lautaro Martinez a doubt despite being included, Dybala has made the cut to round off Scaloni's attack.
Argentina squad in full:
Franco Armani (River Plate), Emiliano Martinez (Aston Villa), Juan Musso (Atalanta),Geronimo Rulli (Villarreal); Marcos Acuna (Sevilla), Juan Foyth (Villarreal), Lisandro Martinez (Ajax), Lucas Martinez Quarta (Fiorentina), Nahuel Molina Lucero (Udinese), Gonzalo Montiel (Sevilla), Nicolas Otamendi (Benfica), German Pezzella (Real Betis), Cristian Romero (Tottenham Hotspur), Nicolas Tagliafico (Ajax); Rodrigo De Paul (Atletico Madrid), Nicolas Dominguez (Bologna), Alejandro Gomez (Sevilla), Giovani Lo Celso (Tottenham Hotspur), Exequiel Palacios (Bayer Leverkusen), Leandro Paredes (Paris Saint-Germain), Guido Rodriguez (Real Betis); Julian Alvarez (River Plate), Emiliano Buendia (Aston Villa), Angel Correa (Atletico Madrid), Joaquin Correa (Lazio), Angel Di Maria (Paris Saint-Germain), Paulo Dybala (Juventus), Nicolas Gonzalez (Fiorentina), Lautaro Martinez (Inter), Lionel Messi (Paris Saint-Germain).