Kerr-Barlow has been included in the Rugby Championship squad despite his impending departure to French club La Rochelle, with the former Chiefs player and the All Blacks' top-ranked No9s Aaron Smith and TJ Perenara out on their own as the three best in the country.
The next best isn't immediately apparent. Blues player Augustine Pulu played two tests for the All Blacks in 2014 but hasn't been sighted in the black jersey since and while he played extremely well for the Blues this year and would no doubt perform an excellent role as a back-up to Smith and Perenara, Pulu is now 27 and the selectors might seek to take a longer-term approach.
Sam Nock, Pulu's teammate at the Blues, is only 21 and is likely to be monitored closely over the next six months or so, and the same applies to Te Toiroa Tahuriorangi, a 22-year-old former Hurricane who has just signed with the Chiefs.
Both men are former New Zealand Under-20 players and are likely to be in the frame more than Bryn Hall (25) and 23-year-old Mitchell Drummond, the Crusaders duo who worked extremely well together in a championship-winning side.
The supremacy of Aaron Smith and Perenara, and the reliability and toughness of Kerr-Barlow, has meant that halfback has been a position of strength for the All Blacks. Kerr-Barlow's departure won't necessarily change that but it will increase the importance of identifying those worthy of extra attention.
"We think we've got to grow our depth there," All Blacks selector Grant Fox admitted to Radio Sport's Kent Johns this morning. "It's not so clear for us. Tawera has had a great season - we don't penalise guys for going away.
"If there's a tight call... then clearly you're going to favour the person who's staying but right at the moment Tawera has still got a lot to contribute. He doesn't go until the end of the season and we've still got a bit of thinking to do as to who's the next halfback.
"Those three are clearly out in front and then there's a wee bit of a gap.
"We're going to have to give somebody an opportunity at some stage - it may not be this year, it may be next year."
Fox and his fellow selectors will, however, have faith that someone will make a strong case for selection. A few years ago there was a "shortage" at lock and then at hooker, both areas of strength now.
"All Blacks' history is littered with stories of 'you give a guy an opportunity and they step up'," Fox said.
First-five is similar to the extent that now that Aaron Cruden has left, Beauden Barrett and Lima Sopoaga are the two best No10s in the country, with Damian McKenzie probably the next best, albeit with limited time in the position.
He was used mainly as a fullback at the Chiefs, but now that Cruden has left the franchise and Colin Cooper has replaced Dave Rennie, McKenzie will be the No10 around whom the Chiefs build their backline from next season.
McKenzie has been included in the All Blacks squad as a "utility" - able to play either first-five or fullback, with Steve Hansen confirming Crusaders' No10 Richie Mo'unga was also on his radar.