The 24-year-old fullback is immensely talented and can be a matchwinner but equally can go missing and that was no better illustrated than during his erratic season with the Warriors.
One of the biggest criticisms is that the difference between his best and worst is far too great and it's a reason why the Warriors secured England fullback Sam Tomkins for the next three years.
Locke still did enough, however, to be included in the 24-man Kiwis squad where he will probably start the World Cup as backup to incumbent fullback Josh Hoffman. Locke has played four tests as well as two games for New Zealand Maori.
"I wanted to make sure we had two specialist fullbacks," Kearney said. "Obviously Kevin had an up-and-down year with the Warriors but ... what I didn't want to do was shuffle around and put wingers or centres back at fullback.
"It's the World Cup and you need specialists in specialist positions. Everyone knows what Kevin can do at his best. It's my job, and the team and staff, to provide an environment to get the best out of Kevin and I'm confident we can do that."
Locke's inclusion meant there was no room for Sam Perrett, who has been a fixture of the side since 2007. Kearney actually has plenty of cover at fullback with Jason Nightingale, Krisnan Inu and Roger Tuivasa-Sheck having all played there at NRL or international level.
Tuivasa-Sheck is one of two newcomers to the squad, along with Roosters teammate Sam Moa.
The 20-year-old winger has made an incredible impression in his first season in the NRL, winning a premiership and being named Dally M Winger of the Year.
He was part of a wider Kiwis squad for this year's Anzac test but has forced his way into the squad and could be first-choice along with recalled Warriors winger Manu Vatuvei.
Vatuvei was dropped for last year's end-of-year test against Australia and was also missing for the Anzac test but his form in 2013 warrants inclusion.
"I just know in that environment over there, greasy grounds, if you can get the ball to [Vatuvei] close to the tryline that he's a good chance to score," Kearney said. "He will be a real asset in the UK, I'm sure of that."
Moa is one player with considerable experience playing in the UK, having spent three years with Hull FC before joining the Roosters this year. He earned a World Cup spot ahead of Warriors prop Sam Rapira and Penrith's Sam McKendry, who broke his neck earlier this year but remarkably returned for five games at the end of the season.
The 27-year-old Moa played for the Junior Kiwis alongside Vatuvei and Thomas Leuluai but has played five tests for Tonga, including the 2008 World Cup and this year's mid-year test against Samoa.
New Zealand squad for the rugby league World Cup starting in the UK on October 27 (NZT):
Backs: Kieran Foran (Manly Sea Eagles, 9 tests), Bryson Goodwin (South Sydney Rabbitohs, 4), Josh Hoffman (Brisbane Broncos, 3), Krisnan Inu (Canterbury Bulldogs, 5), Shaun Johnson (Warriors, 2), Thomas Leuluai (Warriors, 30), Kevin Locke (Warriors, 4), Jason Nightingale (St George Illawarra Dragons, 17), Roger Tuivasa-Sheck (Sydney Roosters, 0), Manu Vatuvei (Warriors, 20), Dean Whare (Penrith Panthers, 2)
Forwards: Jesse Bromwich (Melbourne Storm, 3), Greg Eastwood (Bulldogs, 18), Alex Glenn (Broncos, 6), Tohu Harris (Melbourne Storm, 1), Sam Kasiano (Bulldogs, 1), Issac Luke (Rabbitohs, 23), Simon Mannering (c - Warriors, 30), Ben Matulino (Warriors, 14), Sam Moa (Roosters, 0), Frank-Paul Nu'uausala (Roosters, 9), Frank Pritchard (Bulldogs, 24), Elijah Taylor (Warriors, 4), Jared Waerea-Hargreaves (Roosters, 12).
