Marc Wilson is one of three Pompey players to receive international call-ups for their country next month.
The defender is named in the Republic of Ireland squad to face World Cup quarter-finalists Argentina in Dublin on August 11.
Wilson, who has represented Ireland at under-18, 19 and 21 levels, received his first call up to the senior squad in March against Brazil although he did not feature.
Aaron Mokoena is set to return to South Africa after being named in the squad to face Ghana in the Soccer City Stadium, Johannesburg on August 9.
Blues team-mate Kevin-Prince Boateng is likely to feature against him, having been included in the Ghana squad.
Boateng enjoyed a good World Cup in South Africa, with his national team reaching the quarter-finals. He also scored his first goal for Ghana in their 2-1 victory against the United States.
For Mokoena, who captained the host nation at the World Cup, the tournament was more of a disappointment with South Africa failing to progress out of the group stages – although they did beat France 2-1 in their final match.