Katoa remains in an Auckland hospital after suffering three head knocks in the space of 90 minutes while playing for Tonga against New Zealand in the Pacific Cup almost a fortnight ago.
The 25-year-old required oxygen after he suffered seizure activity on the sidelines and was rushed to hospital where he underwent surgery due to bleeding of the brain.
Storm boss Justin Rodski said Katoa had been steadily improving but still had a "long way to go" and, following his Melbourne hospital stay, could spend time in a rehabilitation centre.
"It's been obviously a really challenging few weeks, both for him, the club, his family and he's in a stable condition," Rodski said at the club headquarters on Friday.
"He's been improving which is really pleasing, but he's still got a long way to go in terms of his short-term, medium-term recovery.
"The next step for us is getting him back to Australia, so we're hopeful that over the weekend or early next week we can get him back to Melbourne ... and returns to hospital for a period of time for further assessment, to see some specialists here, to be under the care of our doctor here.
"From there we'll be able to determine the next steps for his recovery."
Rodski said it was too early to know whether Katoa would be able to play in 2026, or indeed again.
"I don't know, it's very early and we haven't really looked at that and this point.
"We're just focused on his recovery and his health in the short term at the moment and to even speculate or consider that at this point, it's just far too early.
"We'd love to see him in 2026, clearly, as he's probably been one of our best two or three players in the last two years, but at this point it's really not even something that's on our radar."
If Katoa was to miss 2026, Melbourne would almost certainly have Katoa's salary wiped from their cap given the injury was suffered in a representative game.Â
Rodski said the club had been in touch with the NRL about the investigation into Tonga's handling of Katoa.
It's understood much of the focus is on whether Katoa should have been cleared to play after suffering a heavy knock in the warm up, which was deemed to not require a HIA.
He then passed a HIA after another knock to the head in the first half, before returning and suffering a third blow that ended his game.
The NRL has wrapped up the probe, but won't announce findings until Katoa is back home.
"We've been working with the NRL and they are conducting the investigation into the circumstances of what took place," Rodski said.
"Clearly a really serious incident and something that needs and requires an investigation.
"We're really comfortable with the process the NRL has taken and once that's concluded we will then be able to understand the facts ... and from there the NRL will decide what takes place.
"For us, we're concerned, clearly it was serious but at the same time our focus has been about Eli and his recovery."
