Potential World Cup bolter Garang Kuol will miss at least one A-League Men game to spearhead the Young Socceroos in their U20 Asian Cup qualifiers in Kuwait.
Central Coast teen Kuol, who will join Newcastle United in January, is among the Socceroos contenders who had six A-League Men games to push their case for Graham Arnold's Qatar 2022 squad.
He has already missed one game after the Mariners' opening-round clash with the Newcastle Jets was washed out, with the rescheduled fixture yet to be confirmed.
Now Kuol will also miss Sunday's away game against Wellington Phoenix, plus potentially another game, if the Jets fixture is played within the next two weeks.
The prodigiously-talented 18-year-old will instead look to impress against youth internationals from Kuwait, India and Iraq on October 15, 17 and 19 (AEDT) respectively at Ali Sabah Al-Salem Stadium.
The games were originally to be held in Iraq in the September international window but Australia withdrew citing safety concerns before the games were postponed, moved to Kuwait City and the Young Socceroos were re-instated.
The Mariners expected to have Kuol and fellow youngster Nectarios Triantis available for their round-three home game against Perth Glory on October 23.
"Whilst disappointing to lose two first-team players, congratulations to both Garang and Nectar on their selection in the Australian under 20's squad," the club said on Twitter.
"We are hoping for their safe return in preparation for our match against Perth Glory in two weeks' time."
The top team in group H, plus potentially the runner-up, will earn qualification to the U20 Asian Cup in Uzbekistan.
The top four teams at that tournament will qualify for the U20 World Cup.
"We are very thankful for the support of clubs, both in Australia and abroad, for their ongoing support of Australia's national youth team programs and in doing so, allowing us to field the best teams possible and enabling their players to showcase their talent on the international stage," Young Socceroos coach Trevor Morgan said.