Read more: Kearney: Decision made to 'protect' Mannering
"I'm positive because that is the reality," he said. "There is a certain expectation we have helped to create over the last 20 months and nothing changes with regards to that expectation."
Kearney has developed impressive depth over the last few years and players like Tohu Harris, Kevin Proctor, Martin Taupau, Sam Moa and Peta Hiku are all seasoned NRL campaigners, even if they lack test match experience. But it will be hard to replace certain individuals - and contemplate a three-test series against England with a rookie halves combination and a brand new captain.
Kearney wouldn't be drawn on who might take the armband, saying he had "a couple of players in mind" and all would be revealed on Thursday with the squad is announced.
Kearney said the decision to pull Mannering out was taken to "protect" the long-serving skipper, as he had not sufficiently recovered from an outgoing gastric issue.
"Tests haven't confirmed a major issue but he hasn't really got any better," said Kearney. "It's [been done] to protect Simon.
"He would want to get away on tour, to try and do what is best for the team in whatever condition he is in. He can be his own worst enemy in that sense."
"While tests we've conducted haven't revealed anything to cause alarm, Simon still isn't right and requires further assessment," added Warriors head doctor John Mayhew.
Mannering has missed just one Warriors match in the last three years, as well as playing 11 out of a possible 12 tests for the Kiwis.
The England tour begins on October 23 with a warm-up game against Leeds, with the three tests scheduled for Hull (November 1), London's Olympic Stadium (November 7) and Wigan (November 14).
Kiwis who won't fly to the UK
Simon Mannering 41 tests
Thomas Leuluai 34
Manu Vatuvei 28
Kieran Foran 20
Jared Waerea-Hargreaves 17
Shaun Johnson 14
Dallin Watene-Zelezniak 0