"Simon will be sorely missed for his leadership, experience and work ethic," admitted Kidwell. "[But] I wanted to make the decision based on what is best for Simon. I gave him that [extra] week [before Perth] out of respect for what he has done for the jersey. If he was on track he was definitely coming on tour but there were a few minor hiccups there."
Mannering was progressing well in his recovery until a training session last Sunday, when he pulled up sore, leading to another visit to the surgeon on Monday.
"We made a collective decision based on evidence from the surgeon, physio, Simon's feelings and my feelings," said Kidwell. "We wanted Simon to be at 100 per cent."
Mannering is replaced in the squad by James Fisher-Harris, who has been on standby since the team was named two weeks ago. The Penrith youngster, who hails from a small Northland settlement on the Hokianga harbour, was one of the most impressive rookies in the NRL in 2016. The 20-year-old played all but three of the Panthers' games this year, averaging 68 running metres and 22 tackles per game in his debut season.
"He was really high on our list for the initial squad, but narrowly missed out," said Kidwell.
"He's come through the NZRL pathways and has performed at a very high level in the NRL. For a 20-year-old to play first grade like he does is a credit to him."
The Kiwis depart for London tonight, ahead of their opening Four Nations assignment against England in Huddersfield on November 30.