Nketia says the choice is likely to be made before his son's 18th birthday, in early May. While he will give advice and be a sounding board in the decision-making process, the call will ultimately be his son's to make, though Nketia did note what the main factors may be in the eventual decision.
"We need to make a decision on which country he wants to represent, because there is the [Oceania Championships] coming up. It comes down to Edward, whichever way he wants to go. We want a country that will be behind him to help him achieve what he wants to get, and not to represent just for the sake of the sport," he told Radio Sport.
However, there could be another complicating factor. Osei-Nketia has desires to be an All Black, and is on a scholarship at Scots College in Wellington. Nketia says at the moment, rugby is still a major option in his son's sporting future.
"Right now, it's all about rugby to him. He loves rugby, New Zealand, the All Blacks, all these things.
"Back in Canberra, he was in the first XV, pretty good on the field, but obviously Canberra rugby is very different to New Zealand schoolboy rugby, so we have to see what impact he's going to have in New Zealand – the standard is quite high compared to here.
"So if I can look at that side of it, he's leaning towards New Zealand, but with the track, I have no idea. We'll decide as a family what will be best for him."
If he opts for New Zealand, Osei-Nketia could soon be a national record holder, with even his father surprised at how quickly his record has come under threat.
"Watching the race on Saturday night was very exciting, and I'm very proud of him. I knew he would run well, but to that extent – that was a surprise to me.
"Before the race, I was expecting a 10.28 or a 10.3, but then he comes up with this time – it's incredible, he's amazing."
Nketia is now accepting that he will soon be the second fastest member of the family, noting it's "just a matter of time" until his record is surpassed.
"The way he's going, he just needs a good race condition and I'm sure he will get it.
"He still needs to learn the sport, there's a lot he hasn't done. If he goes seriously, he's going to go under the 10 second mark."
That would be unprecedented territory for a New Zealand sprinter, but with so many options on Osei-Nketia's plate, his father will be immensely proud regardless of what his son chooses.
"Whatever he decides to go for, I just want him to succeed. If it's athletics or rugby, either way we're happy with him, and we're going to be behind him all the way."