The Blues play the Lions on June 7 and that's going to be tight for Kaino. He's probably not going to be in contention and that means his likely only opportunity to play before the first test will be for the All Blacks against Samoa on June 16.
Given his experience, the All Blacks coaches might be happy for Kaino to prove he's ready on the back of one hit-out - be it 50 minutes from the start or 30 minutes off the bench - against Samoa.
If he can get through that, they will have to decide if they are then ready to, literally, throw him to the Lions the following week.
It will be a big call because the physicality of the series will be high and the All Blacks will need Kaino at his best. They will need him cutting ball carriers in two and to knock the Lions back behind the gainline.
Maybe the best plan is to not rush him back. Give him time against Samoa and then use him off the bench in the first Lions test with a view to starting him in the second or third.
That option allows for Kaino to play his way back in a more sensible time frame, while opening the door to either Liam Squire or Steven Luatua.
Probably Squire, given the commitment he has made to New Zealand rugby by signing through to the World Cup. Squire, who has impressed in Super Rugby, despite suffering from injury in the early part of the campaign, has most likely been ear-marked to start a few tests later in the year but that plan may have to be pulled forward.
He tackles hard and aggressive, and high impact defence is going to be a major factor in the Lions series.
If he's the natural heir to Kaino, the first test against the Lions would be the right place to find out what he's really made of.
It's also a chance for the coaches to show how much they trust him by saying they think they will get more out of him in the first test than they would an undercooked Kaino.
The other option is the in-form Luatua who might not have quite the same crunch as Squire, but will bring lineout presence, ball skills and that little bit more experience.
Yes he's leaving for Bristol in late July but if he can do a short-term job for the All Blacks before he goes, then why not?