When Shin Tae-Yong first took charge of an Indonesia outfit enduring some of its darkest days in 2020, it was a focus on youth that sparked what is now a remarkable resurgence.
His first major tournament -- that year's ASEAN Championship, which was postponed to 2021 due to the coronavirus pandemic -- saw Indonesia come from nowhere to reach the final.
It ultimately was not to be as they fell to then-record five-time champions Thailand but it proved the start of something special.
The average age of that 30-man squad was just 23.8 years of age -- and the youngsters weren't just making up the numbers. Of the 14 players that started across both legs of the decider, that figure dropped to 22.9 years.
Overnight, the likes of Witan Sulaeman, Pratama Arhan and Alfeandra Dewangga became household names as Indonesia went from strength to strength.
At present, they are the only Southeast Asian nation in the third round of Asian qualifiers for the 2026 FIFA World Cup -- unofficially making them one of the continent's top 18 teams if that measure, and not the world rankings, is used.
A key factor for their steady improvement has been constant introduction of foreign-born players -- who, it must be noted, all have Indonesian heritage through their parents or grandparents, as opposed to a blatant naturalistion of imports which was prevalent in parts of the region in years gone by.
And yet, as Indonesia continue to look to scale greater heights under Shin, it was notable that the teams fielded in recent times have significantly lacked some of the bright young talent that had gotten them this far.
In their most recent outing -- a 2-1 loss to China on Tuesday which was their first defeat in the third round of Asian qualifiers -- Shin's starting XI only had two Indonesian born-and-bred members in Asnawi and Witan.
Five days earlier, it was solely Malik Risaldi representing the homegrown brigade in a 2-2 tie with Bahrain. Last month's impressive draws against Saudi Arabia and Australia also saw no more than two locally-groomed players start.
Whether by coincidence or design, Shin has at least ensured some homegrown presence in his lineups. And it isn't the case that the heritage imports have completely taken over.
The likes of Witan, Rizky Ridho, Egy Maulana and Wahyu Prasetyo remain firmly entrenched in the squad and are regularly utilised off the bench even if they aren't playing from the first whistle.
But it cannot be ignored that there has been a drastic change to the makeup of Indonesia's first-choice lineup, considering the 11 players that started their historic return to the AFC Asian Cup earlier this year featured six local talents.
It is entirely Indonesia's prerogative to explore all avenues to enhance their stocks and they have been consistent in only targeting heritage players, who at least have some semblance of an identity and ties to the country.
Indonesia's football association -- PSSI -- also deserve credit for the aggressive nature in which they have gone about in securing these overseas talent.
While, in the past, naturalisation has been more of a wait-and-see game, with certain players only committing to playing for a new adopted nation once they have deemed their prospects of representing their birth country to be bleak, Indonesia are not content to wait around and be a backup option.
This international window saw debuts for Dutch-Indonesian duo Mees Hilgers and Eliano Reijnders -- the latter being the younger brother of AC Milan and Netherlands star Tijjani.
Both are still only 23 and featuring prominently in one of Europe's strongest leagues -- the Eredivisie. Ordinarily, they would still have had realistic chance of eventually being called up by Netherlands.
Instead, the PSSI have gone right ahead to secure their commitment and, in doing so, would have had to paint an attractive-enough picture to convince such players as to why their allegiance should already be with Indonesia.
Nonetheless, this also revisits the age-old debate over the short-term benefit of readymade additions to the national team versus the longer-term youth infrastructure that should guarantee a steady pipeline of fresh talent.
Perhaps, as the world becomes increasingly cosmopolitan and homogeneous, it will be easier to find heritage players around the world but that is no guarantee. The sure thing remains a robust youth setup that almost mechanically uncovers and nurtures domestic talent.
Even with Shin's first batch of fledgling prospects, Indonesia have already shown they have such an ability, as they should -- given their status as the world's fourth most-populous country.
Aside from Witan, Egy, Asnawi and Arhan, who have all already plied their trade abroad despite their relative youth, the crown jewel has been Marselino Ferdinan -- who burst onto the scene just days after his 17th birthday and had earned a move to Europe with Belgian outfit Deinze by the time he was 18.
Marselino starred for Indonesia at the Asian Cup earlier this year, starting all four games playing a variety of roles and scoring against Iraq, yet has only started one of their four World Cup qualifiers of the current stage.
A lack of minutes -- with Marselino yet to debut since a summer move to Championship outfit Oxford United -- might have contributed, but it is impossible to imagine Shin not calling upon his brightest talent if he did not have the likes of Ragnar Oratmangoen, Rafael Struick or Thom Haye as viable alternatives.
Shin will be aware he cannot be overly reliant on his new faces, as Indonesia edge closer to a year-end assignment that is arguably even bigger than their World Cup qualifying exploits.
The ASEAN Championship is certainly not the World Cup, but it is a tournament that Indonesia have somehow failed to win since its inception in 1996.
In 14 editions, the Indonesians have suffered the agony of a runners-up finish a record six times. They reached the semifinals on another three occasions and have only failed to make it out of the group stage four times.
Probability dictates that they should have become champions of Southeast Asia by now. As the region's sole remaining representatives in the Asian qualifiers, they will -- by default -- be viewed as one of the favourites, meaning expectations among a football-mad country have never been higher.
And yet, they will most likely have to do it without all their overseas-based imports.
With the ASEAN Championship falling outside an official FIFA international window, clubs are not obliged to release players for national team duties.
There may be one or two exceptions but it is likely that Indonesia's title challenge will be led by those playing in the domestic Liga 1 and elsewhere around the region.
Basically, Shin will once again have to turn to the homegrown prospects that started it all -- further emphasising how, at the end of the day, bringing through their own talent still matters.
As Indonesia aim higher and higher, there is room for both the foreign-based heritage imports and the born-and-bred Indonesians.
Fitting it all together will be Shin's balancing act.