He was probably New Zealand's best Super Rugby halfback in 2012, making the wider All Black training squad, only to be cut when the numbers had to be crunched.
The rationale was that the selectors wanted Aaron Smith -- too good to leave out -- and one veteran, who they decided was Piri Weepu because he had wider skills.
At the end of that year when there was room for three halfbacks in the squad, it was the emerging Tawera Kerr-Barlow who was called up.
When Weepu lost his form and fitness last year, TJ Perenara was brought in and that felt like the end of the road for Ellis. He was playing his heart out, delivering mature, controlled performances for the Crusaders ... but there was no apparent interest from the All Blacks.
Unwanted for three years of the World Cup cycle, surely he won't be called up in the fourth?
Well, that's the thing -- the All Blacks have given Perenara a fair crack and have seen him continue to be a tremendous athlete but not progress that far towards becoming a tremendous player.
His decision-making continues to be laboured and a little muddled, and he hasn't learned the art of clearing the ball at speed.
His long-term future remains enormous, but the All Black selectors aren't yet sure whether they would trust him to be on the bench for a big World Cup game.
Smith, as long as he's fit, is going to play in the big games and be kept out there for as long as he can go. Sometimes that will be 80 minutes; other times it will be 75, maybe 70 or even 65 depending on the pace and intensity.
Come the World Cup, the All Blacks are going to need a closer at halfback, someone who can play out the closing minutes in a calm, accurate and composed manner.
That, at the moment, is not Perenara. It is probably not Kerr-Barlow either -- he is probably going to struggle to get himself match fit in time to be considered after extensive knee surgery last month.
It's not the young and promising Augustine Pulu either. His time will come -- but not next year.
There is, really, only one man for the job ... and it is Ellis. And while it might seem a surprise if he is called up, it probably won't be to him -- he's had a fair idea it could happen.
The selectors had to see Perenara and Kerr-Barlow play -- even Pulu, too. If Ellis had been involved in the past three years, he would have restricted the game time of the younger men and the selectors would have been less certain about who could do what.
What they have done these past three years is learned plenty about Perenara and Kerr-Barlow and armed themselves with knowledge coming into World Cup year.
What they know is that neither Perenara nor Kerr-Barlow are anywhere near finished products, so there is likely to be a role for the veteran Ellis.
