"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, 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 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, 27, has 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 this year but remarkably returned for five games at the end of the season.